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 ...
When r.SSR.Stencil is enabled, there is wrong logic observed.
UE - Rendering - Graphics Features - Dec 19, 2025When r.SSR.Stencil is enabled, the areas with high roughnesss are not discarded and Unlit materials are incorrectly handled. See the linked EPS case (Additional Info URL) for a full explanation of ...
Crash when a StateTree-related Parameter is of a type that includes two nested arrays with the same name (due to FPropertyChangedEvent::ArrayIndicesPerObject using array names to map to their changed indices)
UE - Framework - Dec 19, 2025This issue was reported in the context of adding and setting parameters on StateTrees, Tasks and related assets, but its root cause lies in the structure FPropertyChangedEvent and can possibly affec ...
Call In Editor functions not working in blueprints
UE - Editor - Developer Usability - Dec 19, 2025Context When selecting a component on an actor, any CallInEditor functions on the component's class appear as buttons in the details panel. Problem The CallInEditor functions don't execute in Blu ...
WorldToClip/ClipToWorld transform in materials not behaving as expected
UE - Graphics Features - Dec 19, 2025In 5.3, the specified code will return all 0 or very small as expected. However in 5.4.4 and onwards (also checked in 5.6.1 & 5.7.1), it returns very large numbers. ...
Substrate's coverage node does not skip unlit emissive part which have no coverage
UE - Rendering - Graphics Features - Substrate - Dec 18, 2025Substrate's coverage node doesn't seem to cull masked pixels of unlit emissive slabs. This is an important optimization when using masked unlit particles. When using a lit slab, the instructions for ...
Section::TrimSection resulting in bad key values at start and end of trim range
UE - Anim - Sequencer - Dec 17, 2025The trim process inserts keys at the start or end of the range depending if you specify Trim Left or Right, I'm finding that Trim right is inserting a key at the end of the section that is incorrect ...
Automated tests DynamicSubobjectInstancing and NonNativeInstancedSubobjects (CoreUObject group) fail
UE - Framework - Dec 15, 2025The DynamicSubobjectInstancing and NonNativeInstancedSubobjects automation tests fail. ...
[AI] StateTree fails to compile after copy/pasting a state with a task that binds to required event on the state's enter conditions
UE - AI - StateTree - Dec 14, 2025StateTree appears to keep an incorrect reference to the event from the source tree rather than re-establishing the property binding to the new tree's event. This happens when copy/paste of the state ...
FormatName is not added to the display name of gpu events in some cases.
UE - Foundation - Insights - Dec 12, 2025If the breadcrumb events have no metadata but the metadata spec contains a format name, the format name is not added to the display name and the user cannot see it. GPU Profiler 2.0. The trace they ...