Custom UVs don't store information properly in layered materials.

UE - Rendering - Architecture - Materials - May 9, 2022

[Link Removed] I have this set up so that FX artists can stack UV manipulations, so I don't want to just have all the UV manipulation in the layer with the base color, even though that does give me ...

After importing morph target: Ensure condition failed: Referencing SkeletalRenderGPUSkin.cpp

Tools - Sep 23, 2017

Hit handled ensure when dragging the slider in Morph Target PreviewLogOutputDevice: Error: Ensure condition failed: DynamicData->MorphTargetWeights.Num() == LODModel.MorphTargetVertexInfoBuffers.Get ...

Crash caused by a race condition in Nanite::DispatchBasePass()

UE - Rendering - Graphics Features - Nanite - Feb 25, 2026

Nanite::BuildShadingCommands() launches two asynchronous tasks: ShadingCommands.SetupTask ShadingCommands.BuildCommandsTask BuildCommandsTask is responsible for modifying ShadingCommands.Commands ...

ACineCameraAttachMount's "Target Actor" constraint does not work with Spawnables or Replaceables in Sequencer

UE - Virtual Production - Tools - Virtual Camera - Aug 12, 2025

Constraints (UTickableConstraint) are usually created throuh the "Animation" tab available in the Editor's "Animation Mode". When created through that interface while Sequencer is open, the internal ...

MetalRHI Asserts When Using "Profile GPU" With RHI-Thread/Parallel-Execution

UE - Graphics Features - Sep 14, 2016

When the RHI thread is enabled (with or without parallel-execution) for Metal it isn't currently possible to run "profilegpu" because the GPU timestamp emulation code isn't multi-thread safe and pro ...

EQS Overlap test no longer recognizes custom Collision Object Channel

UE - AI - Nov 12, 2019

Environment Queries Ignore tests for Custom Collision Object Overlaps. Note: The expected behavior seems to have worked in 4.21, After following the steps to reproduce, I can verify a successful de ...

Certain UPROPERTY values are not updated during auto-recompile

UE - Gameplay - Blueprint - Aug 4, 2016

Sometimes manual recompile is required to make a blueprint actually recompile data-only changes, but not always. If the last manual compile was with default values, then changes are not updated. If ...

Crash on exit PIE when playing with more than one player on Linux

UE - Platform - Linux - Oct 3, 2016

When playing in non-single player game in the editor (either set # players or check dedicated server checkbox), the editor will crash when the play session ends. Regression: Yes - editor does not c ...

BP - Exclusive nativization will fail at cook time if an Actor BP class enabled for nativization includes a Component BP that's not enabled for nativization in its component list.

UE - Gameplay - Blueprint - Apr 26, 2017

This happens because the Blueprinted component is not also enabled for nativization, but the nativized Actor BP tries to use it as a native class type. Current workaround: Ensure that the Blueprint ...

~FStaticMesh() can crash with race condition

UE - Graphics Features - Mar 21, 2017

UDN user reported frequent crashes in FStaticMesh::~FStaticMesh() on DrawListLinks[i]->Remove(false); Crash went away after adding critical sections to FStaticMesh::LinkDrawList(), FStaticMesh::Unl ...