I am on Windows 8 and I have never used ZSNES in fullscreen in the time I've had my current computer. ZSNES usually works perfectly for me. I was on ZSNES, and my appeared to crash. The music was still playing perfectly, but my controller (Xbox One controller) wasn't registering despite being plugged in, so I wasn't quite sure if my game had crashed or not, so instead of resetting the game like I normally would, I set ZSNES to fullscreen.
The music stopped and the game went to complete black. I couldn't even open up the ZSNES menu or press Esc. I had to alt-tab my way back to my desktop and close ZSNES on the taskbar to leave the program. When I try opening up ZSNES again, it assumes I still want to be in fullscreen, but it's still just black and I can't Esc or open up the ZSNES menu. It gives me this error message.

What's happening and what am I ought to do?