Thank you for the detailed report! This is a known area of friction with Unreal Engine's asset handling, particularly since UE 5.3+ introduced breaking changes in how UAssets are managed.
Here are a few things to try and be aware of:
Workaround for reimporting in UE 5.4+
The Reimport item was removed from the Asset menu in UE 5.4 and later. Instead, you can reimport a file by:
- Select the file you want to reimport via the
Import button on the Content Drawer.
- Click
YES on the overwrite confirmation dialog that appears.
This should trigger the correct reimport flow.
UE 5.3+ naming constraint
Starting with UE 5.3, Epic introduced a breaking change where imported .skel, .json, and .atlas files can no longer share a common prefix. For example:
- ❌
skeleton.skel and skeleton.atlas will not work.
- ✅
skeleton-data.skel and skeleton.atlas will work.
If your files share the same base name, this could be causing the reimport to fail silently, leaving the old textures in place. Try renaming your export files so the skeleton data file and atlas file do not share an identical prefix before reimporting.
If you must fully re-import
If the reimport continues to not update the textures correctly, the most reliable approach is to:
- Manually delete the old Spine assets (atlas, skeleton data, and textures) from the Content Browser.
- Re-export from the Spine Editor with correctly named files (observing the prefix rule above).
- Re-import everything fresh using the
Import button.
- Re-wire any references in your Blueprints or materials to point to the newly imported assets.
This is unfortunately a limitation introduced by Epic's UE 5.3+ regression. A bug report was filed with Epic but it appears they have not addressed it, so these workarounds remain the recommended approach.
Since you've also reported this on GitHub, the team will be able to investigate further if there is a spine-ue specific issue beyond the UE asset handling regression.
