Unreal Engine Issues
Unreal Engine Issues
Material Parameter Collection Track doesn't work in UMG Preview from 5.7
UE - Editor - UI Systems - UMG - Feb 12, 2026The UMG editor allows us to add a Material Parameter Control track to an animation. This track makes it possible to animate parameters used in a material. Designers can scrub the timeline and previe ...
Division by zero causing NaN/Inf on USkeletalMeshComponent::UpdateRigidBodyScaling() when setting scale to zero and back
UE - Simulation - Core - Feb 11, 2026Up to UE 5.5, skeletal mesh physics did not get updated when the component's scale changed. This was improved on January 2025 with CL 39190335, which addressed [Link Removed] ...
Missing logging or error when applying an anim instance to a skeleton that the anim instance doesn't match.
UE - Anim - Runtime - Feb 9, 2026Currently, we detect whether an anim instance is supported by the skeletal mesh and, if it isn't, unreference the instance, but we don't error or warn the user that this happened. This leads to conf ...
Using PCG, StaticMeshComponentPropertyOverride only takes effect when the flag ExecuteOnTheGPU is off.
UE - World Creation - Procedural Tools - Feb 9, 2026StaticMeshComponentPropertyOverride only takes effect when the flag ExecuteOnTheGPU is off. All error checking for StaticMeshComponentPropertyOverride turns off when the flag ExecuteOnTheGPU is off ...
Animation compression deadlock
UE - Anim - Runtime - Anim Blueprints - Feb 5, 2026The deadlock occurs when attempting to cancel compression during animation sequence destruction. The compression thread ends up deadlocking with the game thread, which is the one requesting the canc ...
Possible leak related to using Nanite meshes for Landscape
UE - Graphics Tools - Terrain - Landscape - Feb 5, 2026A licensee reported that the Bulk data for the nanite mesh generated for Landscape proxies can leak in the editor. It could appear as the normal BulkData “leadk” related to fulling loading an Asset ...
Material Functions are incorrectly listed in the Layer Asset list
UE - Rendering - Architecture - Materials - Feb 3, 2026Since UE 5.7, Material Functions are included in the Layer Asset list of the Material Layers of an instanced material using material layers. It is also possible to drag and drop Material Functions ...
Ending a GameplayAbility from an AbilityTask created by the same GameplayAbility does not correctly end the AbilityTask, and it continues ticking.
UE - Gameplay - Gameplay Ability System - Feb 2, 2026When a GameplayAbility is ended from within a child AbilityTask, the AbilityTask is not cleaned up correctly. As a result, even though the GameplayAbility is no longer active, the AbilityTask contin ...
Compatible Skeleton Animation does not retarget the same on duplicate skeleton
UE - Anim - Rigging - Retargeting - Jan 29, 2026If a mesh is exported from the engine, reimported as a new skeleton and mesh, and then marked as a compatible skeleton. Animation will have slightly different rotations playing on the skeleton. ...
Crash when enabling Nanite on a Mesh using an OptimusDeformer
UE - Anim - Rigging - Deformer - Jan 29, 2026When a skeletal mesh has a deformer present and then nanite support is enabled and applied. (the deformer in question was hsasset://DeformerGraph/Deformers/DG_LinearBlendSkin_Morph_Cloth_RecomputeNo ...