Static lights become stationary after toggling visiblity of level in packaged build

UE - Rendering - Graphics Features - Jun 11, 2025

In 5.5, there is a regression with baked lighting where static lights become stationary lights when a level is hidden and then made visible again. This happens in packaged builds and shows up as sta ...

Insufficient precision of Decode71 function

UE - Rendering - Architecture - Shaders - Jun 5, 2025

Encode71 and Decode71 in DeferredShadingCommon.ush are functions that convert 8-bit values ​​to 7-bit values ​​and mask values, and licensees have reported that the accuracy is insufficient when usi ...

Local lights appear broken when baking lighting with GPU Lightmass

UE - Rendering - Graphics Features - Jun 2, 2025

Encountered an issue where local lights appear to be broken when baking lighting with GPU Lightmass. See screenshots attached. Tested regression in //UE5/Release-5.5 @ CL40574608 and the issue does ...

Multiple setter functions in UMaterialEditingLibrary always return false even when the parameter is correctly set on the MaterialInstance.

UE - Rendering - Architecture - Materials - May 30, 2025

In Unreal Engine, materials can expose parameters that can then be modified via instances (MaterialInstanceConstant). The UMaterialEditingLibrary provides several functions to modify these parameter ...

TSR and TAA history accumulation gets reset when taking viewport screenshots or when clicking outside the tree in the outliner

UE - Rendering - Graphics Features - May 30, 2025

TSR (and TAA) history accumulation gets reset when taking viewport screenshots or when clicking on an empty area in the outliner (when a tree item is selected). This can cause an undesirable issue w ...

GLTFExporter indexing issue

UE - Editor - Content Pipeline - glTF - May 29, 2025

Hi, I also ran into an issue when exporting a skeletal mesh that has multiple sections that all share the same material slot. It looks like the index buffer that's constructed is incorrect. In GLTF ...

Search field in 'Quickly Add to Project' fails with Chinese Pinyin input unless manually focused

UE - Editor - UI Systems - Localization - May 28, 2025

A licensee reported that under the Chinese language setting in UE5, using the “Quickly Add to Project” button results in incorrect or ignored input when entering text via Pinyin IME. If the user sta ...

Iris - Subobjects marked COND_InitialOnly not replicated

UE - Networking - Iris - May 23, 2025

When adding replicated subobjects to the registered subobjects list, you can set replication conditions to control how the subobject is considered for replication. Without Iris enabled, a COND_Initi ...

[CrashReport][GPUCrash] UpdateRadianceCaches

UE - Rendering - Graphics Features - Ray Tracing - May 19, 2025

#31 crash out of 7783 in UE 5.7.4 on Windows#3 crash for UE - Rendering - Graphics Features in UE 5.7.4 on Windows#1 crash for UE - Rendering - Graphics Features - Ray Tracing in UE 5.7.4 on Windows ...

Changes to Instanced Properties default value on BP not propagated to placed actors in the opened level

UE - Foundation - May 15, 2025

In UE versions 5.4 and onwards (as of CL 42589677 in Main), when an Instanced UObject property is defined in an Actor Blueprint, modifying the default value in the Blueprint does not propagate the c ...