Unreal Engine Issues
Unreal Engine Issues
Cooker is asserting in Class.h on UE 5.7.1
UE - Core - Systems - Dec 18, 2025From the linked EPS case: ---------------------------- In UE 5.7 there were some changes to how Enum member names are stored. This change introduces an assert when cooking using the Editor Debug e ...
Unable to interact or collide with geometry collection after Removal on Sleep or Break timer finishes, yet unbroken piece continue to render
UE - Runtime - Simulation - Dec 18, 2025Context: A static mesh is able to have a geometry collection generated from it using the Fracture editing mode. It can be fractured in many different ways, and when acted upon by a chaos field agent ...
If a child blueprint class has an Instanced/EditInlineNew object property, that property will always be detected as changed by the property editor (i.e. it will show a "Revert" arrow on that property), even if its properties are identical to the parent.
UE - Framework - Blueprint Editor - Dec 17, 2025Context: Blueprint classes can use Instanced/EditInlineNew object property specifiers to create and edit subobjects directly in the editor. Problem: If a child blueprint class has an Instanced/Edit ...
Section::TrimSection resulting in bad key values at start and end of trim range
zComponent - Archive - Dec 17, 2025The trim process inserts keys at the start or end of the range depending if you specify Trim Left or Right, I'm finding that Trim right is inserting a key at the end of the section that is incorrect ...
[WorldPartition][CellTransformer] ActorComponents registered with wrong world from UWorldPartition::ApplyRuntimeCellsTransformerStack
UE - Engine Scaling - Streaming - World Partition - Dec 17, 2025There is a risk of actor components registering with the wrong world when reconstructed from UWorldPartition::ApplyRuntimeCellsTransformerStack. The repro case is arguably a bad usage, but it was th ...
Viewport stuttering during orbit/zoom navigation
UE - Rendering - Features - Dec 17, 2025Received a report of persistent stutters in the editor when trying to navigate in the viewport, including asset editor viewports like the Skeletal mesh editor and control rig editor. Hardware used ...
A chaos vehicle that moves at very high speeds with CCD enabled on the vehicle sometimes has a collision response that is abnormal where the vehicle loses a significant amount of speed when colliding with dynamic objects configured as One Way Interaction
UE - Runtime - Character - Dec 16, 2025Context: Continuous Collision Detection (CCD) is being used on a Chaos Vehicle to avoid tunneling issues with certain surfaces as it prevents any missed collisions between fast moving particles and ...
Paper2D: Editor hangs when assigning Sprite Atlas Group to Sprite
UE - Gameplay - Paper2D - Dec 16, 2025In UE 5.3 and later, assigning a Sprite Atlas Group to a UPaperSprite asset can cause the editor to hang and eventually crash. This behavior has been reproduced in 5.3, 5.6, and a recent UE5-main so ...
[WorldPartition][CellTransformer] ISM Cell Transformer breaks component hierarchy when child component are transformed
UE - Engine Scaling - Streaming - World Partition - Dec 15, 2025This case is related to [Link Removed] Closed but is not a duplicate. Please make sure to download the attached project a ...
Automated tests DynamicSubobjectInstancing and NonNativeInstancedSubobjects (CoreUObject group) fail
UE - Framework - Dec 15, 2025The DynamicSubobjectInstancing and NonNativeInstancedSubobjects automation tests fail. ...