Unreal Engine Issues

Backwards-compatibility broken for the CDOs of Python-generated Unreal Types because of missing redirectors

Previously, all Unreal Types generated by python scripts would be created inside package "/Engine/PythonTypes". This was changed by [CL 32478991 in ue5-main branch], which meant to "remove the restr ...

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 ...

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

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 ...

Editor/Game Ensure hit with RayTracing enabled on AMD GPU

A Static Mesh asset will trigger an ensure when generating building the ray tracing acceleration structure on AMD GPUs. ...

Params in material instance disappear when grouping is changed in material with a material layer

If there is a texture parameter within a specific material attribute stream in the base material and also within the base material layer, they must have the same parameter group otherwise the parame ...

Missing texture assets cause warnings on editor start: LogStreaming: Warning: Failed to read file '../../../Engine/Plugins/Developer/PlasticSourceControl/Resources/Icon128.png' error.

There are a number of missing texture assets which are failing to be read when the editor opens. This is causing a warning to be thrown each time the editor opens, potentially causing CI/CD tests (i ...

Startup Movies in Lyra Flicker and trigger ensure: "Only one system can use the SlateThread at the same time. GetMoviePlayer is not compatible with PreLoadScreen."

When adding startup movies to Lyra, the movie playback flickers and an ensure conditions fails with the message: Ensure condition failed: bSuccess [File:D:\build\++UE5\Sync\Engine\Source\Runtime\M ...