Umm... Unexpected crash?

I was playing on a multiplayer server, _{(eu.mineplex.com)} and i wanted to go into fullscreen mode. _{(this was previously working)} I have pressed F11, _{(key to go to fullscreen mode)} and suddenly, i crashed... Can someone explain me why this happened? I have read ma crash report, and found this:

java.lang.IllegalStateException: Keyboard must be created before you can read events

What on earth is going on?

?!

Edit: This is not a duplicate, i wasn't adding/removing monitors, i just pressed F11... And it happens on 1.8.8, Not 1.4.x...