While a previous question regarding this has been closed without answers, this doesn't help to solve the problem.
From time to time Netbeans will cause this behavior, but it's hard to say exactly what's happening or why. Logging out of one account and logging into another will almost always trigger this bug.
What happens, visually at least, is that the app menu has no icons and can't seem to draw itself. It's impossible to capture a screen grab.
Is there some particular log to look into?