diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9eb1eaf..7b249fd 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -80,6 +80,7 @@ Previous classification is not required if changes are simple or all belong to t
 - Fixed warnings CS8603 and CS8025 in:
   - `Encamina.Enmarcha.AI`.
   - `Encamina.Enmarcha.AspNet`
+  - `Encamina.Enmarcha.Bot`
 - Corrected a typo in the Spanish error message in `ResponseMessages.es.resx` from "ha encontrar" to "ha encontrado".
  
 ## [8.1.5]
diff --git a/Directory.Build.props b/Directory.Build.props
index c9298dd..a9f63ec 100644
--- a/Directory.Build.props
+++ b/Directory.Build.props
@@ -16,8 +16,8 @@
   </PropertyGroup>
 
   <PropertyGroup>
-    <VersionPrefix>8.1.6</VersionPrefix>
-    <VersionSuffix></VersionSuffix>
+    <VersionPrefix>8.1.7</VersionPrefix>
+    <VersionSuffix>preview-01</VersionSuffix>
   </PropertyGroup>
 
   <!--
diff --git a/src/Encamina.Enmarcha.AI.QuestionsAnswering.Abstractions/IMetadataProcessor.cs b/src/Encamina.Enmarcha.AI.QuestionsAnswering.Abstractions/IMetadataProcessor.cs
index e2397e5..92d388f 100644
--- a/src/Encamina.Enmarcha.AI.QuestionsAnswering.Abstractions/IMetadataProcessor.cs
+++ b/src/Encamina.Enmarcha.AI.QuestionsAnswering.Abstractions/IMetadataProcessor.cs
@@ -19,7 +19,7 @@ public interface IMetadataProcessor
     /// <returns>
     /// A read only collection of answers processed with given metadata options.
     /// </returns>
-    Task<IReadOnlyCollection<IAnswer>> ProcessAnswersAsync(IEnumerable<IAnswer> answers, MetadataOptions metadataOptions, CancellationToken cancellationToken);
+    Task<IReadOnlyCollection<IAnswer>> ProcessAnswersAsync(IEnumerable<IAnswer> answers, MetadataOptions? metadataOptions, CancellationToken cancellationToken);
 
     /// <summary>
     /// Process a message to obtain metadata options from it.
diff --git a/src/Encamina.Enmarcha.AI.QuestionsAnswering.Abstractions/IQuestionRequestOptions.cs b/src/Encamina.Enmarcha.AI.QuestionsAnswering.Abstractions/IQuestionRequestOptions.cs
index a561cf4..70c6a80 100644
--- a/src/Encamina.Enmarcha.AI.QuestionsAnswering.Abstractions/IQuestionRequestOptions.cs
+++ b/src/Encamina.Enmarcha.AI.QuestionsAnswering.Abstractions/IQuestionRequestOptions.cs
@@ -13,5 +13,5 @@ public interface IQuestionRequestOptions
     /// <summary>
     /// Gets the metadata options.
     /// </summary>
-    MetadataOptions MetadataOptions { get; }
+    MetadataOptions? MetadataOptions { get; }
 }
diff --git a/src/Encamina.Enmarcha.AI.QuestionsAnswering.Abstractions/QuestionRequestOptions.cs b/src/Encamina.Enmarcha.AI.QuestionsAnswering.Abstractions/QuestionRequestOptions.cs
index 90057bc..c6a2d1c 100644
--- a/src/Encamina.Enmarcha.AI.QuestionsAnswering.Abstractions/QuestionRequestOptions.cs
+++ b/src/Encamina.Enmarcha.AI.QuestionsAnswering.Abstractions/QuestionRequestOptions.cs
@@ -25,5 +25,5 @@ public QuestionRequestOptions(IEnumerable<string> sources)
     public virtual IReadOnlyCollection<string> Sources { get; } = Array.Empty<string>();
 
     /// <inheritdoc/>
-    public virtual MetadataOptions MetadataOptions { get; init; }
+    public virtual MetadataOptions? MetadataOptions { get; init; }
 }
diff --git a/src/Encamina.Enmarcha.AI.TextsTranslation.Abstractions/ITextTranslationRequest.cs b/src/Encamina.Enmarcha.AI.TextsTranslation.Abstractions/ITextTranslationRequest.cs
index 9d1fa94..7b7c7c1 100644
--- a/src/Encamina.Enmarcha.AI.TextsTranslation.Abstractions/ITextTranslationRequest.cs
+++ b/src/Encamina.Enmarcha.AI.TextsTranslation.Abstractions/ITextTranslationRequest.cs
@@ -10,7 +10,7 @@ public interface ITextTranslationRequest
     /// <summary>
     /// Gets the language to translate from.
     /// </summary>
-    CultureInfo FromLanguage { get; init; }
+    CultureInfo? FromLanguage { get; init; }
 
     /// <summary>
     /// Gets the collection of languages to translate.
diff --git a/src/Encamina.Enmarcha.AI.TextsTranslation.Abstractions/TextTranslationRequest.cs b/src/Encamina.Enmarcha.AI.TextsTranslation.Abstractions/TextTranslationRequest.cs
index 77a6e65..79f4b6a 100644
--- a/src/Encamina.Enmarcha.AI.TextsTranslation.Abstractions/TextTranslationRequest.cs
+++ b/src/Encamina.Enmarcha.AI.TextsTranslation.Abstractions/TextTranslationRequest.cs
@@ -8,7 +8,7 @@ namespace Encamina.Enmarcha.AI.TextsTranslation.Abstractions;
 public class TextTranslationRequest : ITextTranslationRequest
 {
     /// <inheritdoc/>
-    public virtual CultureInfo FromLanguage { get; init; }
+    public virtual CultureInfo? FromLanguage { get; init; }
 
     /// <inheritdoc/>
     public virtual ICollection<CultureInfo> ToLanguages { get; init; } = new List<CultureInfo>();
diff --git a/src/Encamina.Enmarcha.Bot.Abstractions/Dialogs/DialogsProviderBase.cs b/src/Encamina.Enmarcha.Bot.Abstractions/Dialogs/DialogsProviderBase.cs
index 09987a5..f889b38 100644
--- a/src/Encamina.Enmarcha.Bot.Abstractions/Dialogs/DialogsProviderBase.cs
+++ b/src/Encamina.Enmarcha.Bot.Abstractions/Dialogs/DialogsProviderBase.cs
@@ -51,18 +51,18 @@ protected DialogsProviderBase(IServiceProvider serviceProvider)
     }
 
     /// <inheritdoc/>
-    public virtual Dialog GetById(string dialogId) => GetDialogByType(dialogsById?[dialogId], d => FilterById(d, dialogId));
+    public virtual Dialog? GetById(string dialogId) => GetDialogByType(dialogsById?[dialogId], d => FilterById(d, dialogId));
 
     /// <inheritdoc/>
-    public virtual Dialog GetByIntent(string dialogIntent) =>
+    public virtual Dialog? GetByIntent(string dialogIntent) =>
         GetDialogByType(dialogsByIntent?[dialogIntent.ToUpperInvariant()], d => FilterByIntent(d, dialogIntent));
 
     /// <inheritdoc/>
-    public virtual Dialog GetByName(string dialogName) =>
+    public virtual Dialog? GetByName(string dialogName) =>
         GetDialogByType(dialogsByName?[dialogName.ToUpperInvariant()], d => FilterByName(d, dialogName));
 
     /// <inheritdoc/>
-    public virtual bool TryGetById(string dialogId, out Dialog dialog)
+    public virtual bool TryGetById(string dialogId, out Dialog? dialog)
     {
         if (dialogsById == null)
         {
@@ -78,7 +78,7 @@ public virtual bool TryGetById(string dialogId, out Dialog dialog)
     }
 
     /// <inheritdoc/>
-    public virtual bool TryGetByIntent(string dialogIntent, out Dialog dialog)
+    public virtual bool TryGetByIntent(string dialogIntent, out Dialog? dialog)
     {
         if (dialogsByIntent == null)
         {
@@ -94,7 +94,7 @@ public virtual bool TryGetByIntent(string dialogIntent, out Dialog dialog)
     }
 
     /// <inheritdoc/>
-    public virtual bool TryGetByName(string dialogName, out Dialog dialog)
+    public virtual bool TryGetByName(string dialogName, out Dialog? dialog)
     {
         if (dialogsByName == null)
         {
@@ -110,20 +110,20 @@ public virtual bool TryGetByName(string dialogName, out Dialog dialog)
     }
 
     /// <inheritdoc/>
-    public virtual Dialog GetByType(Type dialogType, Func<Dialog, bool> filterExpression = null) => GetDialogByType(dialogType, filterExpression);
+    public virtual Dialog? GetByType(Type dialogType, Func<Dialog, bool>? filterExpression = null) => GetDialogByType(dialogType, filterExpression);
 
     /// <inheritdoc/>
-    public virtual T GetByType<T>(Func<Dialog, bool> filterExpression = null) where T : Dialog => GetDialogByType<T>(filterExpression);
+    public virtual T? GetByType<T>(Func<Dialog, bool>? filterExpression = null) where T : Dialog => GetDialogByType<T>(filterExpression);
 
     /// <inheritdoc/>
-    public virtual bool TryGetByType(Type dialogType, out Dialog dialog, Func<Dialog, bool> filterExpression = null)
+    public virtual bool TryGetByType(Type dialogType, out Dialog? dialog, Func<Dialog, bool>? filterExpression = null)
     {
         dialog = GetDialogByType(dialogType, filterExpression);
         return dialog != null;
     }
 
     /// <inheritdoc/>
-    public virtual bool TryGetByType<T>(out T dialog, Func<Dialog, bool> filterExpression = null) where T : Dialog
+    public virtual bool TryGetByType<T>(out T? dialog, Func<Dialog, bool>? filterExpression = null) where T : Dialog
     {
         dialog = GetDialogByType<T>(filterExpression);
         return dialog != null;
@@ -169,7 +169,7 @@ private static IDictionary<string, Type> BuildFromIntent(IEnumerable<Dialog> dia
         return result;
     }
 
-    private Dialog GetDialogByType(Type dialogType, Func<Dialog, bool> filterPredicate)
+    private Dialog? GetDialogByType(Type? dialogType, Func<Dialog, bool>? filterPredicate)
     {
         if (dialogType == null)
         {
@@ -180,7 +180,7 @@ private Dialog GetDialogByType(Type dialogType, Func<Dialog, bool> filterPredica
         return (serviceScope.ServiceProvider.GetServices(dialogType) as IEnumerable<Dialog>)?.FirstOrDefault(d => filterPredicate == null || filterPredicate(d));
     }
 
-    private T GetDialogByType<T>(Func<Dialog, bool> filterPredicate) where T : Dialog
+    private T? GetDialogByType<T>(Func<Dialog, bool>? filterPredicate) where T : Dialog
     {
         using var serviceScope = serviceProvider.CreateScope();
         return serviceScope.ServiceProvider.GetServices<T>()?.FirstOrDefault(d => filterPredicate == null || filterPredicate(d));
diff --git a/src/Encamina.Enmarcha.Bot.Abstractions/Dialogs/IDialogProvider.cs b/src/Encamina.Enmarcha.Bot.Abstractions/Dialogs/IDialogProvider.cs
index 1c577a2..79b3c3c 100644
--- a/src/Encamina.Enmarcha.Bot.Abstractions/Dialogs/IDialogProvider.cs
+++ b/src/Encamina.Enmarcha.Bot.Abstractions/Dialogs/IDialogProvider.cs
@@ -14,7 +14,7 @@ public interface IDialogProvider
     /// <returns>
     /// A valid <see cref="Dialog"/>.
     /// </returns>
-    Dialog GetById(string dialogId);
+    Dialog? GetById(string dialogId);
 
     /// <summary>
     /// Tries to get a <see cref="Dialog"/> from its unique identifier.
@@ -28,5 +28,5 @@ public interface IDialogProvider
     /// <returns>
     /// Returns <see langword="true"/> if a valid <see cref="Dialog"/> is found by its unique identifier; otherwise, returns <see langword="false"/>.
     /// </returns>
-    bool TryGetById(string dialogId, out Dialog dialog);
+    bool TryGetById(string dialogId, out Dialog? dialog);
 }
diff --git a/src/Encamina.Enmarcha.Bot.Abstractions/Dialogs/IDialogTypeProvider.cs b/src/Encamina.Enmarcha.Bot.Abstractions/Dialogs/IDialogTypeProvider.cs
index 99ead44..18e14f3 100644
--- a/src/Encamina.Enmarcha.Bot.Abstractions/Dialogs/IDialogTypeProvider.cs
+++ b/src/Encamina.Enmarcha.Bot.Abstractions/Dialogs/IDialogTypeProvider.cs
@@ -17,7 +17,7 @@ public interface IDialogTypeProvider
     /// <returns>
     /// A valid <see cref="Dialog"/>.
     /// </returns>
-    Dialog GetByType(Type dialogType, Func<Dialog, bool> filterExpression = null);
+    Dialog? GetByType(Type dialogType, Func<Dialog, bool>? filterExpression = null);
 
     /// <summary>
     /// Gets a <see cref="Dialog"/> by its type from a generic type parameter.
@@ -27,7 +27,7 @@ public interface IDialogTypeProvider
     /// <returns>
     /// A valid <see cref="Dialog"/>.
     /// </returns>
-    T GetByType<T>(Func<Dialog, bool> filterExpression = null) where T : Dialog;
+    T? GetByType<T>(Func<Dialog, bool>? filterExpression = null) where T : Dialog;
 
     /// <summary>
     /// Tries to get a <see cref="Dialog"/> from its type.
@@ -42,7 +42,7 @@ public interface IDialogTypeProvider
     /// <returns>
     /// Returns <see langword="true"/> if a valid <see cref="Dialog"/> is found by its type; otherwise, returns <see langword="false"/>.
     /// </returns>
-    bool TryGetByType(Type dialogType, out Dialog dialog, Func<Dialog, bool> filterExpression = null);
+    bool TryGetByType(Type dialogType, out Dialog? dialog, Func<Dialog, bool>? filterExpression = null);
 
     /// <summary>
     /// Tries to get a <see cref="Dialog"/> by its type from a generic type parameter.
@@ -57,7 +57,7 @@ public interface IDialogTypeProvider
     /// <returns>
     /// Returns <see langword="true"/> if a valid <see cref="Dialog"/> is found by its type; otherwise, returns <see langword="false"/>.
     /// </returns>
-    bool TryGetByType<T>(out T dialog, Func<Dialog, bool> filterExpression = null) where T : Dialog;
+    bool TryGetByType<T>(out T? dialog, Func<Dialog, bool>? filterExpression = null) where T : Dialog;
 }
 
 #pragma warning restore S2360 // Optional parameters should not be used
diff --git a/src/Encamina.Enmarcha.Bot.Abstractions/Dialogs/IIntendedDialogProvider.cs b/src/Encamina.Enmarcha.Bot.Abstractions/Dialogs/IIntendedDialogProvider.cs
index 44b7ee9..7c35695 100644
--- a/src/Encamina.Enmarcha.Bot.Abstractions/Dialogs/IIntendedDialogProvider.cs
+++ b/src/Encamina.Enmarcha.Bot.Abstractions/Dialogs/IIntendedDialogProvider.cs
@@ -14,7 +14,7 @@ public interface IIntendedDialogProvider
     /// <returns>
     /// A valid <see cref="Dialog"/>.
     /// </returns>
-    Dialog GetByIntent(string dialogIntent);
+    Dialog? GetByIntent(string dialogIntent);
 
     /// <summary>
     /// Tries to get a <see cref="Dialog"/> from its intent.
@@ -28,5 +28,5 @@ public interface IIntendedDialogProvider
     /// <returns>
     /// Returns <see langword="true"/> if a valid <see cref="Dialog"/> is found by its intent; otherwise, returns <see langword="false"/>.
     /// </returns>
-    bool TryGetByIntent(string dialogIntent, out Dialog dialog);
+    bool TryGetByIntent(string dialogIntent, out Dialog? dialog);
 }
diff --git a/src/Encamina.Enmarcha.Bot.Abstractions/Dialogs/INamedDialogProvider.cs b/src/Encamina.Enmarcha.Bot.Abstractions/Dialogs/INamedDialogProvider.cs
index 95496f9..a2fb83f 100644
--- a/src/Encamina.Enmarcha.Bot.Abstractions/Dialogs/INamedDialogProvider.cs
+++ b/src/Encamina.Enmarcha.Bot.Abstractions/Dialogs/INamedDialogProvider.cs
@@ -14,7 +14,7 @@ public interface INamedDialogProvider
     /// <returns>
     /// A valid <see cref="Dialog"/>.
     /// </returns>
-    Dialog GetByName(string dialogName);
+    Dialog? GetByName(string dialogName);
 
     /// <summary>
     /// Tries to get a <see cref="Dialog"/> from its name.
@@ -28,5 +28,5 @@ public interface INamedDialogProvider
     /// <returns>
     /// Returns <see langword="true"/> if a valid <see cref="Dialog"/> is found by its name; otherwise, returns <see langword="false"/>.
     /// </returns>
-    bool TryGetByName(string dialogName, out Dialog dialog);
+    bool TryGetByName(string dialogName, out Dialog? dialog);
 }
diff --git a/src/Encamina.Enmarcha.Bot.Abstractions/Dialogs/NamedComponentDialogBase.cs b/src/Encamina.Enmarcha.Bot.Abstractions/Dialogs/NamedComponentDialogBase.cs
index e489ac5..4c23392 100644
--- a/src/Encamina.Enmarcha.Bot.Abstractions/Dialogs/NamedComponentDialogBase.cs
+++ b/src/Encamina.Enmarcha.Bot.Abstractions/Dialogs/NamedComponentDialogBase.cs
@@ -21,7 +21,7 @@ protected NamedComponentDialogBase() : this(null)
     /// Initializes a new instance of the <see cref="NamedComponentDialogBase"/> class.
     /// </summary>
     /// <param name="dialogId">The unique identifier for this dialog.</param>
-    protected NamedComponentDialogBase(string dialogId) : base(dialogId)
+    protected NamedComponentDialogBase(string? dialogId) : base(dialogId)
     {
     }
 
diff --git a/src/Encamina.Enmarcha.Bot.Abstractions/Dialogs/NamedDialogBase.cs b/src/Encamina.Enmarcha.Bot.Abstractions/Dialogs/NamedDialogBase.cs
index 97db91a..f505a2a 100644
--- a/src/Encamina.Enmarcha.Bot.Abstractions/Dialogs/NamedDialogBase.cs
+++ b/src/Encamina.Enmarcha.Bot.Abstractions/Dialogs/NamedDialogBase.cs
@@ -21,7 +21,7 @@ protected NamedDialogBase() : this(null)
     /// Initializes a new instance of the <see cref="NamedDialogBase"/> class.
     /// </summary>
     /// <param name="dialogId">The unique identifier for this dialog.</param>
-    protected NamedDialogBase(string dialogId) : base(dialogId)
+    protected NamedDialogBase(string? dialogId) : base(dialogId)
     {
     }
 
diff --git a/src/Encamina.Enmarcha.Bot.Abstractions/QuestionAnswering/SendResponseResult.cs b/src/Encamina.Enmarcha.Bot.Abstractions/QuestionAnswering/SendResponseResult.cs
index 06ca1b9..edb145f 100644
--- a/src/Encamina.Enmarcha.Bot.Abstractions/QuestionAnswering/SendResponseResult.cs
+++ b/src/Encamina.Enmarcha.Bot.Abstractions/QuestionAnswering/SendResponseResult.cs
@@ -36,5 +36,5 @@ public SendResponseResult(ResourceResponse resourceResponse)
     /// <summary>
     /// Gets the resource response.
     /// </summary>
-    public ResourceResponse ResourceResponse { get; init; }
+    public ResourceResponse? ResourceResponse { get; init; }
 }
diff --git a/src/Encamina.Enmarcha.Bot.Skills.QuestionAnswering/Extensions/IServiceCollectionExtensions.cs b/src/Encamina.Enmarcha.Bot.Skills.QuestionAnswering/Extensions/IServiceCollectionExtensions.cs
index bbd4c28..8cfd70c 100644
--- a/src/Encamina.Enmarcha.Bot.Skills.QuestionAnswering/Extensions/IServiceCollectionExtensions.cs
+++ b/src/Encamina.Enmarcha.Bot.Skills.QuestionAnswering/Extensions/IServiceCollectionExtensions.cs
@@ -1,4 +1,6 @@
-using Encamina.Enmarcha.AI.Abstractions;
+#pragma warning disable S2360 // Optional parameters should not be used
+
+using Encamina.Enmarcha.AI.Abstractions;
 using Encamina.Enmarcha.AI.QuestionsAnswering.Abstractions;
 
 using Encamina.Enmarcha.Bot.Skills.QuestionAnswering;
@@ -11,8 +13,6 @@
 
 using ExceptionMessages = Encamina.Enmarcha.Bot.Skills.QuestionAnswering.Resources.ExceptionMessages;
 
-#pragma warning disable S2360 // Optional parameters should not be used
-
 namespace Microsoft.Extensions.DependencyInjection;
 
 /// <summary>
diff --git a/src/Encamina.Enmarcha.Bot.Skills.QuestionAnswering/QuestionAnsweringDialog.cs b/src/Encamina.Enmarcha.Bot.Skills.QuestionAnswering/QuestionAnsweringDialog.cs
index e23720e..1848c76 100644
--- a/src/Encamina.Enmarcha.Bot.Skills.QuestionAnswering/QuestionAnsweringDialog.cs
+++ b/src/Encamina.Enmarcha.Bot.Skills.QuestionAnswering/QuestionAnsweringDialog.cs
@@ -61,7 +61,7 @@ public QuestionAnsweringDialog(string id, QuestionAnsweringDialogServices questi
     /// <inheritdoc/>
     public override async Task<DialogTurnResult> BeginDialogAsync(DialogContext dc, object options = null, CancellationToken cancellationToken = default)
     {
-        ResourceResponse response = null;
+        ResourceResponse? response = null;
 
         if (dc.Context.Activity.Type == ActivityTypes.Message && !string.IsNullOrWhiteSpace(dc.Context.Activity.Text))
         {
@@ -85,7 +85,7 @@ public override async Task<DialogTurnResult> BeginDialogAsync(DialogContext dc,
         return await dc.EndDialogAsync(response, cancellationToken);
     }
 
-    private static IActivity BuildMessageActivity(string message, bool withVerbose, IEnumerable<IAnswer> answers)
+    private static IActivity BuildMessageActivity(string message, bool withVerbose, IEnumerable<IAnswer>? answers)
     {
         var activity = MessageFactory.Text(message, message);
 
@@ -102,7 +102,7 @@ private static bool VerboseFromTurnContextValue(ITurnContext turnContext)
         return turnContext.Activity.Value is JObject activityValue && (activityValue[Constants.ActivityValueVerbose]?.Value<bool>() ?? false);
     }
 
-    private async Task<QuestionRequest> BuildQuestionRequestAsync(string question, string userId, MetadataOptions metadataOptions, IEnumerable<string> sources, CancellationToken cancellationToken)
+    private async Task<QuestionRequest> BuildQuestionRequestAsync(string question, string userId, MetadataOptions? metadataOptions, IEnumerable<string> sources, CancellationToken cancellationToken)
     {
         var questionRequestOptions = new QuestionRequestOptions(sources)
         {
@@ -119,7 +119,7 @@ private async Task<QuestionRequest> BuildQuestionRequestAsync(string question, s
             };
     }
 
-    private async Task<IEnumerable<IAnswer>> ProcessQuestionResultAsync(QuestionResult result, MetadataOptions metadataOptions, IEnumerable<string> sources, CancellationToken cancellationToken)
+    private async Task<IEnumerable<IAnswer>> ProcessQuestionResultAsync(QuestionResult result, MetadataOptions? metadataOptions, IEnumerable<string> sources, CancellationToken cancellationToken)
     {
         IEnumerable<IAnswer> answers = result.Answers;
 
@@ -141,7 +141,7 @@ private async Task<IEnumerable<IAnswer>> ProcessQuestionResultAsync(QuestionResu
         return answers;
     }
 
-    private async Task<ResourceResponse> SendAnswerAsync(IEnumerable<IAnswer> answers, ITurnContext turnContext, CancellationToken cancellationToken)
+    private async Task<ResourceResponse?> SendAnswerAsync(IEnumerable<IAnswer> answers, ITurnContext turnContext, CancellationToken cancellationToken)
     {
         var verbose = configurationOptions.Verbose || VerboseFromTurnContextValue(turnContext);
 
diff --git a/src/Encamina.Enmarcha.Bot.Skills.QuestionAnswering/QuestionAnsweringDialogServices.cs b/src/Encamina.Enmarcha.Bot.Skills.QuestionAnswering/QuestionAnsweringDialogServices.cs
index 8e933a9..0985ca9 100644
--- a/src/Encamina.Enmarcha.Bot.Skills.QuestionAnswering/QuestionAnsweringDialogServices.cs
+++ b/src/Encamina.Enmarcha.Bot.Skills.QuestionAnswering/QuestionAnsweringDialogServices.cs
@@ -9,10 +9,10 @@
 namespace Encamina.Enmarcha.Bot.Skills.QuestionAnswering;
 
 internal record class QuestionAnsweringDialogServices(ICognitiveServiceFactory<IQuestionAnsweringService> QuestionAnsweringCognitiveServiceFactory,
-    IBotTelemetryClient BotTelemetryClient = null,
-    ISourcesProcessor SourcesProcessor = null,
-    IMetadataProcessor MetadataProcessor = null,
-    IQuestionRequestProcessor QuestionRequestProcessor = null,
-    IQuestionResultProcessor QuestionResultProcessor = null,
-    ISendAnswersProcessor SendAnswersProcessor = null,
-    IIntentResponsesProvider IntentResponsesProvider = null);
+    IBotTelemetryClient? BotTelemetryClient = null,
+    ISourcesProcessor? SourcesProcessor = null,
+    IMetadataProcessor? MetadataProcessor = null,
+    IQuestionRequestProcessor? QuestionRequestProcessor = null,
+    IQuestionResultProcessor? QuestionResultProcessor = null,
+    ISendAnswersProcessor? SendAnswersProcessor = null,
+    IIntentResponsesProvider? IntentResponsesProvider = null);
diff --git a/src/Encamina.Enmarcha.Bot/Adapters/BotCloudAdapterWithErrorHandlerBase.cs b/src/Encamina.Enmarcha.Bot/Adapters/BotCloudAdapterWithErrorHandlerBase.cs
index 1248318..d6c5de9 100644
--- a/src/Encamina.Enmarcha.Bot/Adapters/BotCloudAdapterWithErrorHandlerBase.cs
+++ b/src/Encamina.Enmarcha.Bot/Adapters/BotCloudAdapterWithErrorHandlerBase.cs
@@ -47,7 +47,7 @@ protected BotCloudAdapterWithErrorHandlerBase(IBotAdapterOptions<BotCloudAdapter
     /// <summary>
     /// Gets this adapter's options.
     /// </summary>
-    protected virtual IBotAdapterOptions<BotCloudAdapterWithErrorHandlerBase> Options { get; init; }
+    protected virtual IBotAdapterOptions<BotCloudAdapterWithErrorHandlerBase>? Options { get; init; }
 
     /// <summary>
     /// An error handler that can catch exceptions in the middleware or application.
diff --git a/src/Encamina.Enmarcha.Bot/Extensions/IServiceCollectionExtensions.cs b/src/Encamina.Enmarcha.Bot/Extensions/IServiceCollectionExtensions.cs
index 3881ce7..14b4852 100644
--- a/src/Encamina.Enmarcha.Bot/Extensions/IServiceCollectionExtensions.cs
+++ b/src/Encamina.Enmarcha.Bot/Extensions/IServiceCollectionExtensions.cs
@@ -1,4 +1,6 @@
-using System.Globalization;
+#pragma warning disable S2360 // Optional parameters should not be used
+
+using System.Globalization;
 
 using Encamina.Enmarcha.AI;
 
@@ -29,8 +31,6 @@
 using ExceptionMessages = Encamina.Enmarcha.Bot.Resources.ExceptionMessages;
 using IMiddleware = Microsoft.Bot.Builder.IMiddleware;
 
-#pragma warning disable S2360 // Optional parameters should not be used
-
 namespace Microsoft.Extensions.DependencyInjection;
 
 /// <summary>
@@ -72,7 +72,7 @@ public static IServiceCollection AddBotState<TBotState>(this IServiceCollection
     }
 
     /// <summary>
-    /// Adds a bot transcript logger middleware as singleton using a memory trasncript store.
+    /// Adds a bot transcript logger middleware as singleton using a memory transcript store.
     /// </summary>
     /// <remarks>This extension method uses the <see cref="MemoryTranscriptStore"/> transcript store.</remarks>
     /// <param name="services"> The <see cref="IServiceCollection"/> to add services to.</param>
@@ -85,7 +85,7 @@ public static IServiceCollection AddBotTranscriptLoggerMiddlewareWithInMemorySto
     }
 
     /// <summary>
-    /// Adds a bot transcript logger middleware as singleton using a Blob container as trasncript logger (and store).
+    /// Adds a bot transcript logger middleware as singleton using a Blob container as transcript logger (and store).
     /// </summary>
     /// <remarks>This extension method uses the <see cref="BlobsTranscriptStore"/> transcript store.</remarks>
     /// <param name="services"> The <see cref="IServiceCollection"/> to add services to.</param>
@@ -115,13 +115,13 @@ public static IServiceCollection AddBotTranscriptLoggerMiddlewareWithBlobStore<T
     }
 
     /// <summary>
-    /// Adds a bot transcript logger middleware as singleton using a file storage as trasncript store.
+    /// Adds a bot transcript logger middleware as singleton using a file storage as transcript store.
     /// </summary>
     /// <remarks>This extension method uses the <see cref="MemoryTranscriptStore"/> transcript store.</remarks>
     /// <param name="services"> The <see cref="IServiceCollection"/> to add services to.</param>
     /// <param name="folder">A folder path to place the transcript files.</param>
     /// <param name="overwriteTranscriptFiles">
-    /// A flag to indicate if transcript files should be overriten or not. This is usually helpful for unit test scenariuos. Default value is <see langword="false"/>.
+    /// A flag to indicate if transcript files should be overwritten or not. This is usually helpful for unit test scenarios. Default value is <see langword="false"/>.
     /// </param>
     /// <param name="serviceLifetime">The lifetime for the <see cref="MemoryTranscriptStore"/>.</param>
     /// <returns>The <see cref="IServiceCollection"/> so that additional calls can be chained.</returns>
@@ -227,7 +227,7 @@ public static IServiceCollection AddBotStorageBlob(this IServiceCollection servi
     /// <summary>
     /// Adds a bot middleware.
     /// </summary>
-    /// <typeparam name="TBotMiddleware">The type of a specific bot middlerware. It must implement interface <see cref="IMiddleware"/>.</typeparam>
+    /// <typeparam name="TBotMiddleware">The type of a specific bot middleware. It must implement interface <see cref="IMiddleware"/>.</typeparam>
     /// <param name="services"> The <see cref="IServiceCollection"/> to add services to.</param>
     /// <param name="serviceLifetime">The lifetime for the <typeparamref name="TBotMiddleware"/>.</param>
     /// <returns>The <see cref="IServiceCollection"/> so that additional calls can be chained.</returns>
@@ -239,9 +239,9 @@ public static IServiceCollection AddBotMiddleware<TBotMiddleware>(this IServiceC
     }
 
     /// <summary>
-    /// Adds a bot middlerware from an implementation factory.
+    /// Adds a bot middleware from an implementation factory.
     /// </summary>
-    /// <typeparam name="TBotMiddleware">The type of a specific bot middlerware. It must implement interface <see cref="IMiddleware"/>.</typeparam>
+    /// <typeparam name="TBotMiddleware">The type of a specific bot middleware. It must implement interface <see cref="IMiddleware"/>.</typeparam>
     /// <param name="services"> The <see cref="IServiceCollection"/> to add services to.</param>
     /// <param name="implementationFactory">The factory that creates the service.</param>
     /// <param name="serviceLifetime">The lifetime for the <typeparamref name="TBotMiddleware"/>.</param>
@@ -250,7 +250,7 @@ public static IServiceCollection AddBotMiddleware<TBotMiddleware>(this IServiceC
         where TBotMiddleware : class, IMiddleware
     {
         return services.TryAddType(serviceLifetime, implementationFactory)
-                       .AddType<IMiddleware, TBotMiddleware>(serviceLifetime, serviceProvider => serviceProvider.GetService<TBotMiddleware>());
+                       .AddType<IMiddleware, TBotMiddleware>(serviceLifetime, serviceProvider => serviceProvider.GetService<TBotMiddleware>()!);
     }
 
     /// <summary>
diff --git a/src/Encamina.Enmarcha.Bot/Greetings/LocalizedHeroCardGreetingsOptionsFromTableStorage.cs b/src/Encamina.Enmarcha.Bot/Greetings/LocalizedHeroCardGreetingsOptionsFromTableStorage.cs
index b8a7fa5..4cd41a9 100644
--- a/src/Encamina.Enmarcha.Bot/Greetings/LocalizedHeroCardGreetingsOptionsFromTableStorage.cs
+++ b/src/Encamina.Enmarcha.Bot/Greetings/LocalizedHeroCardGreetingsOptionsFromTableStorage.cs
@@ -36,7 +36,7 @@ internal class LocalizedHeroCardGreetingsOptionsFromTableStorage : ILocalizedHer
     /// The absolute expiration time, relative to now in seconds for a cache to store values retrieved from the Table Storage, to improve performance. Default <c>86400</c> (i.e., 24 hours - 1 day).
     /// </param>
     /// <param name="memoryCache">An optional valid instance of a memory cache to improve performance by storing parameters and values retrieved from the Table Storage.</param>
-    public LocalizedHeroCardGreetingsOptionsFromTableStorage(string tableConnectionString, string tableName, string defaultLocale, double cacheAbsoluteExpirationSeconds = 86400, IMemoryCache memoryCache = null)
+    public LocalizedHeroCardGreetingsOptionsFromTableStorage(string tableConnectionString, string tableName, string defaultLocale, double cacheAbsoluteExpirationSeconds = 86400, IMemoryCache? memoryCache = null)
         : this(tableConnectionString, tableName, CultureInfo.GetCultureInfo(defaultLocale), cacheAbsoluteExpirationSeconds, memoryCache)
     {
     }
@@ -51,7 +51,7 @@ public LocalizedHeroCardGreetingsOptionsFromTableStorage(string tableConnectionS
     /// The absolute expiration time, relative to now in seconds for a cache to store values retrieved from the Table Storage, to improve performance. Default <c>86400</c> (i.e., 24 hours - 1 day).
     /// </param>
     /// <param name="memoryCache">An optional valid instance of a memory cache to improve performance by storing parameters and values retrieved from the Table Storage.</param>
-    public LocalizedHeroCardGreetingsOptionsFromTableStorage(string tableConnectionString, string tableName, CultureInfo defaultLocale, double cacheAbsoluteExpirationSeconds = 86400, IMemoryCache memoryCache = null)
+    public LocalizedHeroCardGreetingsOptionsFromTableStorage(string tableConnectionString, string tableName, CultureInfo defaultLocale, double cacheAbsoluteExpirationSeconds = 86400, IMemoryCache? memoryCache = null)
     {
         Guard.IsNotNullOrWhiteSpace(tableConnectionString);
         Guard.IsNotNullOrWhiteSpace(tableName);
diff --git a/src/Encamina.Enmarcha.Bot/Logging/ApplicationInsightsConversationScopedLoggerEventSource.cs b/src/Encamina.Enmarcha.Bot/Logging/ApplicationInsightsConversationScopedLoggerEventSource.cs
index 5bfe043..4af6039 100644
--- a/src/Encamina.Enmarcha.Bot/Logging/ApplicationInsightsConversationScopedLoggerEventSource.cs
+++ b/src/Encamina.Enmarcha.Bot/Logging/ApplicationInsightsConversationScopedLoggerEventSource.cs
@@ -27,7 +27,7 @@ private ApplicationInsightsConversationScopedLoggerEventSource()
     /// <param name="error">The error message to log.</param>
     /// <param name="applicationName">The name of the application.</param>
     [Event(1, Message = "Sending log to ApplicationInsigthsConversationScopedLoggerProvider has failed. Error: {0}", Level = EventLevel.Error)]
-    public void FailedToLog(string error, string applicationName = null)
+    public void FailedToLog(string error, string? applicationName = null)
     {
         WriteEvent(1, error, applicationName ?? this.applicationName);
     }
diff --git a/src/Encamina.Enmarcha.Bot/Logging/ApplicationInsigthsConversationScopedLogger.cs b/src/Encamina.Enmarcha.Bot/Logging/ApplicationInsigthsConversationScopedLogger.cs
index dfa0305..06acc93 100644
--- a/src/Encamina.Enmarcha.Bot/Logging/ApplicationInsigthsConversationScopedLogger.cs
+++ b/src/Encamina.Enmarcha.Bot/Logging/ApplicationInsigthsConversationScopedLogger.cs
@@ -68,7 +68,7 @@ public bool IsEnabled(LogLevel logLevel)
     }
 
     /// <inheritdoc />
-    public void Log<TState>(LogLevel logLevel, EventId eventId, TState state, Exception exception, Func<TState, Exception, string> formatter)
+    public void Log<TState>(LogLevel logLevel, EventId eventId, TState state, Exception exception, Func<TState, Exception?, string> formatter)
     {
         if (formatter == null)
         {
diff --git a/src/Encamina.Enmarcha.Bot/Middlewares/DetectedLanguageTranslatorMiddleware.cs b/src/Encamina.Enmarcha.Bot/Middlewares/DetectedLanguageTranslatorMiddleware.cs
index d39c89f..0edae60 100644
--- a/src/Encamina.Enmarcha.Bot/Middlewares/DetectedLanguageTranslatorMiddleware.cs
+++ b/src/Encamina.Enmarcha.Bot/Middlewares/DetectedLanguageTranslatorMiddleware.cs
@@ -37,7 +37,7 @@ public class DetectedLanguageTranslatorMiddleware : IMiddleware
     /// A cognitive service provider to locate a language detection and a text translation services from the given names.
     /// </param>
     public DetectedLanguageTranslatorMiddleware(CultureInfo translateToLanguage, IEnumerable<CultureInfo> languageExceptions, string languageDetectionServiceName, string textTranslationServiceName, ICognitiveServiceProvider cognitiveServiceProvider)
-        : this(translateToLanguage, languageExceptions, cognitiveServiceProvider?.GetLanguageDetectionService(languageDetectionServiceName), cognitiveServiceProvider?.GetTextTranslationService(textTranslationServiceName))
+        : this(translateToLanguage, languageExceptions, cognitiveServiceProvider.GetLanguageDetectionService(languageDetectionServiceName), cognitiveServiceProvider.GetTextTranslationService(textTranslationServiceName))
     {
     }
 
@@ -66,7 +66,7 @@ public DetectedLanguageTranslatorMiddleware(CultureInfo translateToLanguage, IEn
     /// any of the exception languages, then it will be translated into the translation language before passing it down the pipeline.
     /// </para>
     /// <para>
-    /// When returning, it also process outgoint activities to translate back.
+    /// When returning, it also process outgoing activities to translate back.
     /// </para>
     /// </summary>
     /// <param name="turnContext">The context object for this turn.</param>
diff --git a/src/Encamina.Enmarcha.Bot/Middlewares/StartActivityTranslatorMiddleware.cs b/src/Encamina.Enmarcha.Bot/Middlewares/StartActivityTranslatorMiddleware.cs
index 4a1fb19..d2ff2db 100644
--- a/src/Encamina.Enmarcha.Bot/Middlewares/StartActivityTranslatorMiddleware.cs
+++ b/src/Encamina.Enmarcha.Bot/Middlewares/StartActivityTranslatorMiddleware.cs
@@ -13,7 +13,7 @@
 namespace Encamina.Enmarcha.Bot.Middlewares;
 
 /// <summary>
-/// Middleware to automatically translate messages sent to consumers duting start activities into the language
+/// Middleware to automatically translate messages sent to consumers during start activities into the language
 /// received as <see cref="Activity.Locale"/>.
 /// </summary>
 /// <remarks>
@@ -31,7 +31,7 @@ public class StartActivityTranslatorMiddleware : IMiddleware
     /// A cognitive service provider to locate a language detection and a text translation services from the given names.
     /// </param>
     public StartActivityTranslatorMiddleware(string textTranslationServiceName, ICognitiveServiceProvider cognitiveServiceProvider)
-        : this(cognitiveServiceProvider?.GetTextTranslationService(textTranslationServiceName))
+        : this(cognitiveServiceProvider.GetTextTranslationService(textTranslationServiceName))
     {
     }
 
diff --git a/src/Encamina.Enmarcha.Bot/Middlewares/TranslatorUtils.cs b/src/Encamina.Enmarcha.Bot/Middlewares/TranslatorUtils.cs
index 84f3552..c711ac8 100644
--- a/src/Encamina.Enmarcha.Bot/Middlewares/TranslatorUtils.cs
+++ b/src/Encamina.Enmarcha.Bot/Middlewares/TranslatorUtils.cs
@@ -22,7 +22,7 @@ internal static class TranslatorUtils
     /// <returns>
     /// The trasnslated text in the given <paramref name="language"/> or the given default value from <paramref name="default"/>.
     /// </returns>
-    internal static string GetTranslation(IDictionary<string, string> translations, CultureInfo language, string @default = @"")
+    internal static string GetTranslation(IDictionary<string, string>? translations, CultureInfo language, string @default = @"")
     {
         return translations != null && (translations.TryGetValue(language.Name, out var value) || translations.TryGetValue(language.Parent.Name, out value)) ? value : @default;
     }
@@ -36,13 +36,13 @@ internal static string GetTranslation(IDictionary<string, string> translations,
     /// <param name="toLanguage">The language to translate to.</param>
     /// <param name="cancellationToken">A cancellation token that can be used to receive notice of cancellation.</param>
     /// <returns>A task that represents the asynchronous error handling operation.</returns>
-    internal static async Task TranslateMessagesAsync(ITextTranslationService translationService, IList<Activity> activities, CultureInfo fromLanguage, CultureInfo toLanguage, CancellationToken cancellationToken)
+    internal static async Task TranslateMessagesAsync(ITextTranslationService translationService, IList<Activity> activities, CultureInfo? fromLanguage, CultureInfo toLanguage, CancellationToken cancellationToken)
     {
         var messageActivities = activities?.Where(a => a.Type == ActivityTypes.Message);
 
         if (messageActivities?.Any() ?? false)
         {
-            // Use an index as translation identifier to keep track of translatable items, which could be more than just the message, since it might also include attachemnts and other elements.
+            // Use an index as translation identifier to keep track of translatable items, which could be more than just the message, since it might also include attachments and other elements.
             var index = 0;
             var translatableItems = new Dictionary<string, string>();
 
diff --git a/src/Encamina.Enmarcha.Bot/Responses/TableStorageResponseProvider.cs b/src/Encamina.Enmarcha.Bot/Responses/TableStorageResponseProvider.cs
index c38ab58..0f36d4c 100644
--- a/src/Encamina.Enmarcha.Bot/Responses/TableStorageResponseProvider.cs
+++ b/src/Encamina.Enmarcha.Bot/Responses/TableStorageResponseProvider.cs
@@ -32,7 +32,7 @@ internal class TableStorageResponseProvider : IIntentResponsesProvider
     /// <param name="defaultLocale">Default locale.</param>
     /// <param name="intentCounterSeparator">
     /// An optional value that represents the intent counter separation (i.e., a value that helps separating the intent
-    /// label from a numeric value that represens its order or instance number). Defaults to '<c>-</c>'.
+    /// label from a numeric value that represents its order or instance number). Defaults to '<c>-</c>'.
     /// </param>
     /// <param name="cacheAbsoluteExpirationSeconds">
     /// An optional value for absolute expiration time in seconds for the cache. Defaults to '<c>86400</c>' seconds.
@@ -43,7 +43,7 @@ public TableStorageResponseProvider(string tableConnectionString,
         string defaultLocale,
         string intentCounterSeparator = @"-",
         double cacheAbsoluteExpirationSeconds = 86400,
-        IMemoryCache memoryCache = null)
+        IMemoryCache? memoryCache = null)
     {
         Guard.IsNotNullOrWhiteSpace(tableConnectionString);
         Guard.IsNotNullOrWhiteSpace(tableName);
@@ -66,11 +66,13 @@ public virtual Task<IReadOnlyCollection<Response>> GetResponsesAsync(string inte
     /// <inheritdoc/>
     public virtual async Task<IReadOnlyCollection<Response>> GetResponsesAsync(string intent, CultureInfo culture, CancellationToken cancellationToken)
     {
-        var intentsByLocale = await memoryCache?.GetOrCreate(CacheKey, async cacheEntry =>
+        var intentsByLocale = memoryCache != null
+        ? await memoryCache.GetOrCreateAsync(CacheKey, async cacheEntry =>
         {
-            cacheEntry.AbsoluteExpirationRelativeToNow = TimeSpan.FromSeconds(cacheAbsoluteExpirationSeconds);
-            return await InitAsync(cancellationToken);
-        }) ?? await InitAsync(cancellationToken);
+             cacheEntry.AbsoluteExpirationRelativeToNow = TimeSpan.FromSeconds(cacheAbsoluteExpirationSeconds);
+             return await InitAsync(cancellationToken);
+        })
+        : await InitAsync(cancellationToken);
 
         return (intentsByLocale.TryGetValue(culture.Name.ToUpperInvariant(), out var responsesByIntent) ||
                 intentsByLocale.TryGetValue(culture.Parent.Name.ToUpperInvariant(), out responsesByIntent) ||
@@ -147,4 +149,4 @@ private sealed class ResponsesTableEntity : ITableEntity
 
         public string Intent => RowKey;
     }
-}
\ No newline at end of file
+}