Startup movies displaying black screen in packaged projects.
Tested with 4.20p3 4135216 and 4.21 4157973
Download Attached 4.19 project.
1. Package Project for Windows 64 and verify movies show on startup. (Sound will be directed to your oculus rift if you have one plugged in)
2. Update to 4.20, Package.
or
1. Create a Movies folder in your content browser
2. Drop movie files into folder
3. In project settings, add the movie(s) and tick "Wait for Movies to Complete"
4. Package project
Result: Sound plays but videos do not appear
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-61092 in the post.