Unreal Engine Issues

Non-deterministic cook due to UModel::LightingGuid

The -DiffOnly cook mode shows that the LightingGuid seems to change every cook. In Lyra, there seems to be 48 such assets that change every cook due to this. ...

Material Instance used textures list shows sample textures used as Input Preview Textures within Material Functions

The value of LLM AudioSummary is not an Audio-related aggregate value.

"stat llm" does not show that the Audio summary value is the sum of Audio related tags. In the attached screenshot, when executing "stat llmfull", the AudioSummary value is less than the sum of "Aud ...

Absolute World Position not returning the correct values in post process material after Temporal Upscale

Fatal Error when setting S RGB to true on a Texture 2D from a Render Target Create Static Texture Editor Only node

This is a regression. Tested in //UE4/Release-4.27 CL#18319896 Fatal Error when setting S RGB to true on a Texture 2D from a Render Target Create Static Texture Editor Only node. ...

Engine crashes when building GPU Lightmass in large scenes

Engine crashes when building GPU lightmass in larger scenes. This does not occur on smaller maps like the Unreal Engine Templates. I was able to reproduce this issue in CitySamples SmallCity map. T ...

Ensure tripped: "Template Mismatch during attachment."

References to external actors are not removed when a data layer is deleted

Data layers still contain references to external actors when they are deleted. ...

VirtualHeightfieldMesh shadow issues

A UDN reported ensure being encountered with VirtualHeightFieldMesh rendering on UE5. Those ensures remain an issue on 5.1 (UE5/Main) as of CL 19779838. [Link Removed] Attempting to repro on PC, th ...

Static meshes disappear after changing a property in the collision category if Enable Async Static Mesh Compilation is false