Unreal Engine Issues

UE-274572

Illegal reference to private object when cooking a child level sequence with a time warp track

Illegal reference to private object when cooking a child level sequence with a time warp track

EPS
Description

Slack: [Link Removed]

Another Slack: [Link Removed]

 

Cook error:

UATHelper: Cooking (Windows): LogSavePackage: Warning: UATHelper: Cooking (Windows): Referencers of MovieSceneTimeWarpSection /Game/ChildSequence.ChildSequence:MovieScene_0.MovieSceneTimeWarpTrack_1.MovieSceneTimeWarpSection_0: UATHelper: Cooking (Windows): LogSavePackage: Warning: MovieSceneTimeWarpTrack /Game/ChildSequence.ChildSequence:MovieScene_0.MovieSceneTimeWarpTrack_1 (2 refs) UATHelper: Cooking (Windows): LogSavePackage: Warning: 0) ObjectProperty /Script/MovieScene.MovieSceneTimeWarpTrack:Sections.Sections PackagingResults: Warning: MovieSceneTimeWarpTrack /Game/ChildSequence.ChildSequence:MovieScene_0.MovieSceneTimeWarpTrack_1 (2 refs) PackagingResults: Warning: 0) ObjectProperty /Script/MovieScene.MovieSceneTimeWarpTrack:Sections.Sections UATHelper: Cooking (Windows): LogSavePackage: Warning: 1) ObjectProperty /Script/MovieScene.MovieSceneTrackEvaluationFieldEntry:Section UATHelper: Cooking (Windows): LogSavePackage: Warning: UATHelper: Cooking (Windows): Referencers of MovieSceneTimeWarpTrack /Game/ChildSequence.ChildSequence:MovieScene_0.MovieSceneTimeWarpTrack_1: PackagingResults: Warning: 1) ObjectProperty /Script/MovieScene.MovieSceneTrackEvaluationFieldEntry:Section UATHelper: Cooking (Windows): LogSavePackage: Warning: MovieScene /Game/ChildSequence.ChildSequence:MovieScene_0 (1 refs) UATHelper: Cooking (Windows): LogSavePackage: Warning: 0) ObjectProperty /Script/MovieScene.MovieScene:Tracks.Tracks UATHelper: Cooking (Windows): LogSavePackage: Warning: UATHelper: Cooking (Windows): Referencers of MovieScene /Game/ChildSequence.ChildSequence:MovieScene_0: PackagingResults: Warning: MovieScene /Game/ChildSequence.ChildSequence:MovieScene_0 (1 refs) PackagingResults: Warning: 0) ObjectProperty /Script/MovieScene.MovieScene:Tracks.Tracks UATHelper: Cooking (Windows): LogSavePackage: Warning: LevelSequence /Game/ChildSequence.ChildSequence (1 refs) UATHelper: Cooking (Windows): LogSavePackage: Warning: 0) ObjectProperty /Script/LevelSequence.LevelSequence:MovieScene PackagingResults: Warning: LevelSequence /Game/ChildSequence.ChildSequence (1 refs) PackagingResults: Warning: 0) ObjectProperty /Script/LevelSequence.LevelSequence:MovieScene UATHelper: Cooking (Windows): LogWindows: Error: appError called: Can't save 'C:/Users/MaxChen/Documents/Unreal Projects/CookWithTimeWarp/Saved/Cooked/Windows/CookWithTimeWarp/Content/NewLevelSequence.uasset': Illegal reference to private object: 'MovieScene /Game/ChildSequence.ChildSequence:MovieScene_0' referenced by 'ChildSequence' (at '/Game/ChildSequence') in its 'MovieScene' property. UATHelper: Cooking (Windows): LogWindows: Error: begin: stack for UAT UATHelper: Cooking (Windows): LogWindows: Error: === Critical error: === UATHelper: Cooking (Windows): LogWindows: Error: UATHelper: Cooking (Windows): LogWindows: Error: Can't save 'C:/Users/MaxChen/Documents/Unreal Projects/CookWithTimeWarp/Saved/Cooked/Windows/CookWithTimeWarp/Content/NewLevelSequence.uasset': Illegal reference to private object: 'MovieScene /Game/ChildSequence.ChildSequence:MovieScene_0' referenced by 'ChildSequence' (at '/Game/ChildSequence') in its 'MovieScene' property. UATHelper: Cooking (Windows): LogWindows: Error: UATHelper: Cooking (Windows): LogWindows: Error: UATHelper: Cooking (Windows): LogWindows: Error: end: stack for UAT PackagingResults: Error: appError called: Can't save 'C:/Users/MaxChen/Documents/Unreal Projects/CookWithTimeWarp/Saved/Cooked/Windows/CookWithTimeWarp/Content/NewLevelSequence.uasset': Illegal reference to private object: 'MovieScene /Game/ChildSequence.ChildSequence:MovieScene_0' referenced by 'ChildSequence' (at '/Game/ChildSequence') in its 'MovieScene' property. PackagingResults: Error: begin: stack for UAT PackagingResults: Error: === Critical error: === PackagingResults: Error: Can't save 'C:/Users/MaxChen/Documents/Unreal Projects/CookWithTimeWarp/Saved/Cooked/Windows/CookWithTimeWarp/Content/NewLevelSequence.uasset': Illegal reference to private object: 'MovieScene /Game/ChildSequence.ChildSequence:MovieScene_0' referenced by 'ChildSequence' (at '/Game/ChildSequence') in its 'MovieScene' property. PackagingResults: Error: end: stack for UAT
Steps to Reproduce

Sample project here:

[Link Removed]
(Note from Ludo: I had to delete the Intermediate/Saved folders, otherwise the editor seems to crash on load)

Without project:

  1. Create a level sequence
  2. Add a child level sequence
  3. Put a time warp track in the child level sequence
  4. Cook

 For debugging the invalid reference error without the complicated Sequence hierarchy data structures:

  1. Take the project above (don’t forget to delete the Intermediate/Saved folders), and grab shelf 51677675
  2. Open the project, and delete the ParentSEQ actor (the ChildSEQ actor should still be in the level though)
  3. Add a Sphere, and add a TestInnerRef component to it
  4. On the TestInnerRef component, set the Sequence property to ChildSEQ. Then, click on the “Toggle Inner Reference” button
  5. Cook.

What the button does is that it finds a TimeWarp curve object in the provided Sequence. The TimeWarp curve object is public, but has outers that are private.

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Fixed
ComponentUE - Anim - Sequencer
Target Fix5.8
Fix Commit53758429
CreatedApr 28, 2025
ResolvedMay 11, 2026
UpdatedMay 29, 2026
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