Program freezes when pressing Print Screen button

Hello,

my problem is, that my running program sometimes freezes when i press the print screen button. The joal sound stops playing music.
The graphical is back to render in a 5 seconds, but the sound keep the silence, and when my program start to play other music files, nothing can be heard.
And for me, the most interesting think is, that i don’t receive exceptions.

Can anyone help me?