I've had the same issue. The palette worked in previous versions of AE, but isn't working in 2025, just a black screen.
Is there a specific version that you are encountering this issue on? Something like 25.1.0 or 25.3.0?
There seems to be some reported issues with 25.3 causing black frames that will require one to clear their cache:
https://www.reddit.com/r/AfterEffects/comments/1laqb9b/just_a_heads_up_the_new_2...