Unreal Engine Issues
Unreal Engine Issues
Resavepackages commandlet strips level package thumbnails
UE - Editor - May 12, 2026When loading thumbnails in FLinkerLoad::SerializeThumbnails, the level asset has two thumbnails. The first one has a size of 0, which causes the loading process to abort early. Since the actual thum ...
Curve Atlas Row Parameter uses derivative ops when Texture Sample connected to curveTime input
UE - Rendering - Architecture - Materials - May 1, 2026When a Curve Atlas Row Parameter node is used with a Texture Sampler connected to the curve time input, the sample type uses derivative ops. This has negative performance implications for Nanite co ...
Open Formats: Interchange Import Runtime - Interchange ImportAssetAsync runtime GLB import — materials, textures, tangents, and shaders non-functional in packaged builds (6 issues, UE 5.7.4)
UE - Editor - Open File Formats - Apr 30, 2026Description* We are using Interchange's `UInterchangeManager::ImportAssetAsync()` to import GLB files at runtime in a packaged (Shipping) application. The orchestration layer (`ImportInternal` in `In ...
[StateTree] Cannot use SetLinkedStateTreeOverrides if the linked asset uses the same schema with a parent context data class of the root tree.
UE - AI - StateTree - Apr 3, 2026If both assets have the same schema (StateTreeComponentSchema), but the root tree has the Context Actor class set to Character and the linked asset is using a Context Actor class of Pawn. So the sch ...
CSM Cached Shadows missing when changing FOV
UE - Rendering - Graphics Features - Shadows - Mar 30, 2026When changing the camera FOV with r.Shadows.CSMCaching enabled, the cached shadows don't appear to be used and shadows are missing. This occurs because the r.Shadow.RadiusThreshold can be low enoug ...
USD Export - crashes when sub level holds level instance
UE - Editor - Content Pipeline - USD - Mar 27, 2026The engine is crashing when the user tries to export from a persistent level with a sub level that contains a level instance. ...
Renamed controls creating duplicate curves in sequencer that once fixed up cause selection issues.
UE - ACT Character - Control Rig - Mar 25, 2026When a control is renamed after it has already been animated in a sequence, the control curve name map needs to be fixed up. Once it is fixed, selecting the control in the world will not map the sel ...
Chooser with Gameplay tag as output causes Evaluate Choose to not compile.
UE - Characters - Animation - Mar 20, 2026When using a No Primary Result Chooser that contains an FGameplayTag parameter, an Evaluate Chooser node using that chooser will cause a compilation error: LogBlueprint: Error: [AssetLog][PathToPro ...
Modular rig - Hindleg thigh bug when switching from IK to FK
UE - ACT Character - Control Rig - Mar 16, 2026The thigh FK controller of the hingleg in modular rig doesn't move the thigh bone, causing bad deformation on the mesh around character's thigh area. ...
Cursor radius set via FSlateApplication::SetCursorRadius is ignored during FHittestGrid hit testing
UE - AI Workflows - UI Systems - Slate - Mar 16, 2026The cursor radius configured through FSlateApplication::SetCursorRadius() is not respected during Slate hit testing. The radius value is correctly stored in FSlateApplication and passed into FHittes ...