In order to be able to help you we need more information:
Computer specification, Windows version and program version, see this topic for what is required and please quote processor and graphics card make/model in full, and also what monitor/screen resolution(s) your are working with.
I would suggest you put this information in your profile signature so we do not have to keep asking for it.
Are the graphics card drivers up to date?
A screen shot of the Program settings, Device options tab would help.
The amount of free space on the hard drive(s) you have.
Was there any error dialog that popped up when the 'crash' occurred, or displayed when restarting the program eg the Send crash log message to Magix, if so what was the message?