I started experiencing something odd with the new SetPlaybackPosition in 4.26.
So, it seems that one cannot call an event from the SequenceDirector, that either directly or indirectly calls a SetPlaybackPosition on the sequence itself. This used to work fine for 4.25 (with the deprecated ScrubTo or JumpTo nodes) but now using SetPlaybackPosition it produces an Ensure failed error. Not sure if it’s a regression of an older bug I read about somewhere (4.17 maybe?)
Do the following simple thing:
Start a new FPS template, C++ Create a simple actor in C++ that holds a UPROPERTY for a ULevelSequencePlayer Also include a UPROPERTY for a ULevelSequence Extend that actor in Blueprint Create a new LevelSequence that does something very simple, for example moves one of the cubes in the scene * Select that sequence from the dropdown for your LevelSequence object reference in your blueprint’s properties At BeginPlay create a new CreateLevelSequencePlayer and set it for your LevelSequencePlayer property (I did it in my blueprint actor) Trigger your sequence to play however you like (at begin play or whatever - I used a box trigger, from within the BP actor mentioned above) *In the sequencer, add your BP actor from above and add an event track that simply aims to skip to some other frame - do that by calling a custom event in the BP actor which then calls SetPlayBackPosition (in my case in an arbitrary marked frame A).
I was basically trying to interrupt normal playback of the cube movement and make it skip to another frame towards the end. The same thing used to work in 4.25 (admittedly though was not using SetPlaybackPosition for this).