AnimationPlayer keyframe resource cache prevents valid deletion of swapped sprite (Ghost Dependency)

[bazsupport]

Tested versions

4.4.1 and 4.5.1

System information

Windows 10

Issue description

I have found a reproducible bug where the editor fails to release a file dependency after it has been swapped out in an AnimationPlayer keyframe. This prevents the file from being cleanly deleted, causing "Unable to open file" errors and failing to show up in the Orphan Resource Explorer.

Steps to reproduce

1. Create a Scene with a Sprite2D and an AnimationPlayer.
2. Create an animation track that keys the texture property of the Sprite2D to use image_A.png.
3. In the animation track (or Inspector), swap the keyframe's value to use image_B.png.
4. Immediately delete image_A.png from the FileSystem.
5. Bug: The console begins spamming ERROR: Unable to open file: res://.godot/imported/image_A.png... even though the file is no longer referenced in the scene.
6. Verification: Open Tools > Orphan Resource Explorer. The deleted file is NOT listed, implying the editor still thinks it has an owner (likely the UndoHistory or Animation resource cache).
7. Fix: The workaround is to close editor, delete .godot folder, and then reopen the editor.

Minimal reproduction project (MRP)

anim keyframe bug.zip

Godot_v4.5.1-stable_win64_dWRKdQnGnZ.mp4

[TokageItLab]

I think there are some cleanup bugs present.

For example, if you change a key's value and "save the scene", and then close Godot, detecting an Orphan Resource is something that should be cleaned up.

However, when you reopen an “unsaved” scene as shown in the video and get an error, this is intended behavior. The animation keys retain references to the resources, and the warning indicates that the actual resource is missing; This is similar to scene dependencies. When you reimport an image, the animation state needs to revert to its previous state.