This appears to happen every time I exit the game, whether it will be losing connection or willfully going to the main menu and pressing exit/quit. The screen turns black as it would usually when exiting full screen. The thing is that it stays black. I am not able to put any input on my Windows computer what-so-ever. This forces a hard restart which isn't something that should be done on a computer often. This started happening after the Empyrea update.
(Also, out of curiosity, can you provide more information about the version of Windows you're using? Does Control+Alt+Delete allow you to close down the program without a hard restart?)