Render Preview is Black but export / render is fine I added a video as texture and the video was not playing even though everything was correct, after a few tries I got into another (way worst) problem. When I render in the work-space (Shift + Z) everything is pure black, but if I render (f12) it renders well. I already deleted the video from the blender file in case it was causing a bug but still everything black. I am using Cycles. I tried with Blender render and everything was fine.
I've discovered the issue. If someone is facing the same problem, I solved by pressing the pause button at the bottom right of the 3d view window, it only appears when on render preview (shift + z)