I tried to make a screen replacement. I performed a handheld camera move around my tv and back in mocha I inserted a videofile and adjusted it to fit the screen. Then I tried to export it (via export rendered clip) and suddenly realized that it only exported a black image with a white placeholder/mask which was originally my inserted video. I was desperately searching for an option to export it like I see it, but unfortunately I was not successful.
Dropbox - File Deleted -> rendered video
Dropbox - File Deleted - mocha