diff --git a/Source/AddProcessor.h b/Source/AddProcessor.h
index 47d64b9a..a326e24d 100644
--- a/Source/AddProcessor.h
+++ b/Source/AddProcessor.h
@@ -25,8 +25,11 @@ class AddProcessor : public ProcessorBase {
       // and the size of myGainLevels isn't zero. If it were zero,
       // getSafeGainLevel(index) will know to use 1.0f for every gain.
 
-      // todo: throw graceful error
-      return;
+      throw std::runtime_error(
+          "AddProcessor: The incoming audio buffer has " + numInputs +
+          std::string(
+              " channels, but the number of specified gain levels is ") +
+          std::to_string(myGainLevels.size()));
     }
 
     const int numTimesToSum = numInputs - 1;
diff --git a/Source/PluginProcessor.cpp b/Source/PluginProcessor.cpp
index b0ce347f..7d3b271c 100644
--- a/Source/PluginProcessor.cpp
+++ b/Source/PluginProcessor.cpp
@@ -509,7 +509,7 @@ const PluginPatch PluginProcessor::getPatch() {
   for (auto& uncastedParameter : this->getParameters()) {
     auto parameter = (AutomateParameterFloat*)uncastedParameter;
     float val = parameter->sample(posInfo);
-    params.push_back(std::make_pair(i, val));
+    params.emplace_back(i, val);
     i++;
   }
 
diff --git a/Source/RenderEngine.cpp b/Source/RenderEngine.cpp
index f78d0a12..12a86362 100644
--- a/Source/RenderEngine.cpp
+++ b/Source/RenderEngine.cpp
@@ -414,7 +414,10 @@ void RenderEngine::transportRewind() {}
 void RenderEngine::prepareProcessor(ProcessorBase* processor,
                                     const std::string& name) {
   if (this->removeProcessor(name)) {
-    // todo: maybe warn the user that a processor was removed.
+    std::cerr << "Warning: a processor with the name \"" << name
+              << "\" already exists and was removed to make room for the new "
+                 "processor."
+              << std::endl;
   };
 
   auto node = m_mainProcessorGraph->addNode(