Form 3 stops printing. Screen not responsive


Hi everyone.
Im printing with the printer for about a month now, and everything went well.
Today i sent a print of 4 hours, and after about 2 hours came to check in on the print.
The screen is black and the buildplatform is not moving.
There is still light and i hear that the printer is not off. When i checked at Preform, its writen that the printer is offline.
Does anybody know what happend? How can i fix this? And what do i need to do so the problem won’t happend again?