I think it doesn't like the "bPlaying == false" expression for the EditCondition meta tag on the UPROPERTY...
You also get these warnings every single time the Sequencer plays through a keyframe on the Frame track [Image Removed]
Expected: Property is bound as a track with no warnings
Result: 4 warnings emitted to the Output Log:
LogMovieSceneECS: Warning: Unable to resolve property 'bPlaying == false' from 'HeterogeneousVolumeComponent' instance 'HeterogeneousVolumeComponent' LogMovieScene: Warning: Unable to resolve property 'bPlaying == false' from 'HeterogeneousVolumeComponent' instance 'HeterogeneousVolumeComponent' LogMovieSceneECS: Warning: Unable to resolve property 'bPlaying == false' from 'HeterogeneousVolumeComponent' instance 'HeterogeneousVolumeComponent' LogMovieScene: Warning: Unable to resolve property 'bPlaying == false' from 'HeterogeneousVolumeComponent' instance 'HeterogeneousVolumeComponent'
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-204764 in the post.
| 2 | 
| Component | UE - Niagara - Cinematics | 
|---|---|
| Affects Versions | 5.4 | 
| Target Fix | 5.8 | 
| Created | Jan 24, 2024 | 
|---|---|
| Updated | Oct 3, 2025 |