The TimeWarp feature in Sequencer cannot be used in UEFN. When I try to play using TimeWarp, I get the error “Disallowed reference to MovieScene.MovieSceneTimeWarpDecoration.” Is this a feature that is only available in UE5?
Please select what you are reporting on:
Unreal Editor for Fortnite
What Type of Bug are you experiencing?
Other
Steps to Reproduce
Please set up a sequencer to animate a skeletal mesh, apply TimeWarp to adjust its playback speed, and then play the map in Fortnite.
Expected Result
It will likely throw an error, and you won’t be able to play it.
Thanks for the report. Time Warp in Sequencer should be allowed in UEFN. Unfortunately there was a bit of oversight here and it’s failing validation because the MovieSceneTimeWarpDecoration class wasn’t properly exposed. A fix has been submitted and should be coming out in 37.10. The bug report for this issue is FORT-942881 and we’ll update this post when the fix has made it into a release.
Wanted to add on to this Bug. We are currently experiencing the same validation error when creating animations within a widget blueprint. The interesting thing is that we are NOT using any time warp or any related settings on any of our animations. Unfortunately we are unable to launch session if this widget blueprint is used in a device, blocking our work. We can’t find any reference to Time Warp within the asset to remove to resolve the validation error.
Thanks for the additional post here about the validation error in the widget blueprint. If you had added a time warp track and then removed it, it would still fail validation because there’s a bug where the internal UMovieSceneTimeWarpDecoration class wasn’t cleaned up properly. I’ve found the issue and will have it fixed in a later release.
Regardless, the validation error has been fixed in 37.10, so this error should not appear again in that release. For the time being, there isn’t a way around this except to rebuild the animation. You could create a 2nd animation sequence, copy/paste the tracks from one to the other, and then delete the initial animation sequence. Sorry for the troubles.
