Thank you so much for your quick response. I’m sorry for reacting so late myself.
The videolayers weren’t accidently put on 3D mode. Figuring out why the rotoscope isn’t working took me a lot of time and I still don’t know why it doesn’t work. I decided to throw away the rotoscope layer and mask the person out. That was quite a task, but in the end it took me less than an hour, so that’s solved.
Thanks again!