I've got an event open right now containing multiple project files utilizing the same footage and audio files. The 2nd project is just a different cut of the exact same files.
The first project I have a transition called "Colorful Circle Transition 06" used to close out the edit. (these are presentations from a live event) The first project renders the circles. The 2nd project, nothing is happening. The transition is there, you can see it on the timeline and the index shows that it's there, but nothing is appearing.
Transition was applied the same way for both projects.