Unreal Engine Issues

Regression: FAnimInstanceProxy memory leak when BeginDestroy() called on UAnimInstance before USkeletalMeshComponent

In UE 5.5, the fix applied by CL 36529858 in ue5-main updated USkeletalMeshComponent::ClearAnimScriptInstance() to call AnimScriptInstance::UninitializeAnimation() on the animation instance. This, i ...

Add Substrate Material Support to Lumen Performance Overview

There is a discrepancy when inspecting Substrate materials in the Lumen Performance Overview. Compared to viewing non-Substrate materials the overview show all surfaces in red indicating that Lumen ...

DMX component in world partitioned level fails cook

Since UE5.5, RegisterComponent has been called during cook process, So unnecessarily references from DMXLibrary to DMXComponent has been added.  There is a workaround to avoid adding references : ...

Converting a modular character to a static mesh can result in a crash or in an asset with corrupted data

[AI] Navigation System can be constructed in situations where the NavigationObjectRepository subsystem is not valid

Investigate and fix all calls where the Navigation System is constructed without the NavigationObjectRepository subsystem being valid.  ...

[AI] "LogNavigation: Warning: UNavigationObjectRepository is required for navigation system operations" when cooking a project with validation enabled

The cook completes with a warning for "LogNavigation: Warning: UNavigationObjectRepository is required for navigation system operations" which causes many CI pipelines to fail as they use treat warn ...

Mirror operation on Physics Asset produces wrong results for constraints, including flipped axes

The Physics Asset Editor has a "mirror" feature that allows physics bodies and constraints to be mirrored from one side of a skeleton to the other. If this operation worked correctly, it could save ...

CreateDynamicMaterialInstance will pull from the base rather than overridden mesh on SkinnedMeshComponent when run from construction script

When UPrimitiveComponent::CreateDynamicMaterialInstance is called on a skinned mesh, and the input material is invalid, we call USkinnedMeshComponent::GetMaterial to get the base material on the exi ...

[AI] Navmesh tiles on different layers get removed while streaming out in WP Dynamic Modifiers Only navmesh

 Streaming out the navmesh and streaming the area back into the world before the GC runs causes the navmesh streamed back into the world to only have navmesh tiles on a layer with tiles that would b ...

Deleting transient actor marks level dirty

The licensee has noticed that the deletion of a transient actor still marks the scene as dirty and asks it to be saved. Checking the source it was noted that the transient flag is not verified on de ...