Problem with exported video : lines/pixels all the way

I

Hi,

I exported a video of mine from Premiere pro, without changing the settings that I usually use. But this time, the video came out like this... I tried different settings, it stays that way. I've tried on another computer, same result. But on a third computer, it worked just fine with the same settings and same Premiere pro version.

What could the problem be?

Thanks for your help !