No picture only voice

[JTRch]

I have only a white blank screen with a little black square in the left down corner. I hear the music and voices from menu, but I don't have a usable picture with MechVM. Installing was no problem for me. My system: Win10 Home 64bit, GTX-1080. I also deactivated the G-Sync in Nvidia Options.

Edit: Problem solved, I had to edit the output from DOSbox to ddraw.