The debuger has many problems, I had some issues like that when trying to debug a second web app while already debugging another one.
When the debugger crashes (happens a lot), leaves behind some orphaned processes, this locks the executable file preventing the IDE deleting it and compile a new one to debug (yup, crapy design, never tells you that there is a problem creating the file, it just silently fails)
Instead of restarting the PC, try to just kill those processes.
As for the bug, it is better if you can reproduce it in a sample proyect and share it, that way you could have more answers from other users.
By the way, it is a shame to see that the staff have the time to go and praise at the moderator that lock a complaing thread but not the time to give you actual support to avoid the complains in the first place:
