Try to defining Form B outside of Form A. When you are closing Form A, the reference to Form B is destroyed by implication and this is why it dies. You should always try to define forms and referencing material outside of the classes should you need them elsewhere. Otherwise, at times, this leads to such issues.
Related Q&A from Samuel Colak
Have a question for an expert?
Please add a title for your question
Get answers from a TechTarget expert on whatever's puzzling you.