Fullscreen Crash

All works well with Minecraft.
Just if I turn the screen to fullscreen with F11 or something else:
Minecraft crashes and i get the message that the fullscreen can´t be toggled and "No OpenGL context found in the current thread".
I already tried to delete "options,txt" and the fullscreen is on true.
But the strange thing is that sometimes it works, but i changed nothing!!!
But it is so ennoying because 90% it crashes so PLEASE can somebody help me?!
Thanks for everyone who try!!!