Unreal Engine Issues
Unreal Engine Issues
MultiProcessCook Shader Symbols fail to write when two workers race and try to write them at the same time
UE - Rendering - Architecture - Shaders - Jan 4, 2026When shadersymbols are requested, cooking shaders writes the symbol files into {Project} /Saved/ShaderSymbols/<PlatformName>. These symbols are written by the function FShaderSymbolExport::Write ...
CreatePatchLibrary is broken
UE - Rendering - Architecture - Shaders - Nov 12, 2025It seems the FEditorShaderCodeArchive.LoadExistingShaderCodeLibrary missed some functions, use FEditorShaderCodeArchive.AddShaderCodeLibraryFromDirectory instead could fix the issue. ...
Build crash when enabling r.CreateShadersOnLoad=1
UE - Rendering - Architecture - Shaders - Nov 10, 2025When "r.CreateShadersOnLoad" is enabled, cooking will crash due to failure to create a shader. This occurs on //UE5/Release-5.5, CL: 41545209 and //UE5/Release-5.6, CL: 45232827 ...
Crash When Loading Cooked Material Assets in Editor Due to Shader Serialization
UE - Rendering - Architecture - Shaders - Aug 27, 2025In Unreal Engine 5.6+, the new shader serialization logic in FShaderMapResourceCode::Serialize does not correctly handle cooked assets that are loaded back into the editor (e.g., from a mounted .pak ...
Insufficient precision of Decode71 function
UE - Rendering - Architecture - Shaders - Jun 5, 2025Encode71 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 ...
Shader Symbols not Generated for Windows Platform when r.Shaders.Symbols=1
UE - Rendering - Architecture - Shaders - Feb 28, 2025Shader symbols are not generated for the Windows platform. Attempts were made to set the r.Shaders.Symbols=1 value in the projects DefaultEngine.ini, the engines ConsoleVariables.ini and the engine ...
Compiling any material in UE 5.5.1 without ShaderCompiler JobCache results in a crash
UE - Rendering - Architecture - Shaders - Jan 15, 2025Compiling any material with r.ShaderCompiler.JobCache=0 causes ShaderCompileWorker to crash. Reproduction steps cause a crash during Editor startup, but this bug may affect other scenarios where mat ...
SingleLayerWater Material crashes when sampling SceneTexture:CustomStencil.
UE - Rendering - Architecture - Shaders - Sep 19, 2024There is a texture mismatch between the expected texture samplers and actual texture samplers for SingleLayerWater materials that use the Material Function StencilMaskCompare. Also tested on UE5.5, ...
Crash when precaching PSOs for decals from non-game thread
UE - Rendering - Architecture - Shaders - Aug 21, 2024During async loading from an AsyncLoading thread, DecalComponent attempts to precache PSOs which can trigger a checkf in StrongObjectPtr.h which are only allowed to be created on a game thread. ...
UE5.4 Regression - crash when disabling shader optimization while raytracing is enabled on D3D12
UE - Rendering - Architecture - Shaders - Jul 15, 2024Certain interactions between a Rect Light with a Light Function and a Post-Process volume lead to a check() when compiling a Ray Tracing PSO for tracing lights. This check() only happens when shader ...