I have an existing Composition with smoke video. I made some changes to the composition and there is now black on the screen around the smoke as though the Alpha Channel is broken. I have other comps in the same project with the same smoke that work fine. So I copied the working comp and when I paste it into the project it shows black around the smoke like the bad comp. I think it must be a setting in the comp of project that is causing this but I can't figure it out. Has some one had this issue before and knows how to fix it.
Screenshots would be great. What changes you made to the comp would also be useful to know. Also, version of AE (down to the last decimal point), system specs, format and codec of the footage, etc. would be good to know.
I just figured it out, thanks.
For the sake of future forum searchers, would you mind sharing what fixed it?