students not added after deleting

[resha007]

when trying to add students after deleting from a wrong grade, the success message was shown. but the student was not added to new grade.

1. deleted student from wrong grade. (1569555989 -nadeesha)
2. go to student->filter->add student
3. select 2019/2020 and grade 12 maths and 12 SB class.
4. completed and success message displayed.
   but the student was not added to the 12SB or grade 12 maths.

[resha007]

when student added with the admission number, the student is displayed on the school.

when student added without the admission number, the student is not displayed on the school and not display any error message.(success message displayed).