Cloth jitters in Movie Render Queue renders when temporal sampling is enabled

UE - Anim - Sequencer - MRQ - Dec 6, 2022

The Cloth simulation time step smoothing is interfering with the substepping fix for multi Temporal Samples by changing the very variable DeltaTime and causing some large errors in the cloth simulat ...

Running the BuildPlugin command results in a warning that ForceCompile is not supported and an error that an item with the same key has already been added

UE - Foundation - Cpp Tools - Automation Tool - Dec 7, 2022

Repro Rate: 5/5 This issue was encountered in the 5.1.0 live launcher build of //UE5/Release-5.1 at CL 23058290 and reproduced by other users. Regression tested against the 5.0.3 live launcher bui ...

Substrate Unlit editor view mode renders black with Blendable GBuffer

UE - Rendering - Features - Shading Models - Mar 18, 2026

When using Substrate materials with SUBSTRATE_GBUFFER_FORMAT==0 (Blendable GBuffer), the Unlit editor view mode renders completely black. TopLayerData.UnlitViewBaseColor is never populated in the bl ...

Translucent Materials no longer reflect light when using Forward Lighting variable

UE - Graphics Features - Jun 7, 2016

Translucent materials are no longer showing light reflections in scene when using r.forwardlighting 1 with lights. This is a regression from functionality in 4.11.2. This no longer works with 4.12 ...

AI Move To Location zeros velocity each call, causing the AI Pawn to freeze if told to move again before reaching destination

UE - AI - Sep 12, 2016

AI Move To Location causes AI to lose velocity each time it is called, resulting in a freeze in movement on each call. Regression: Yes Worked: 4.12.5 (CL 3039270) Broken: 4.13.0 (CL 3106830) Funct ...

"Enable Stencil Test" Mobile crash

UE - Graphics Features - Sep 10, 2019

A material with 'enable stencil test' will crash on mobile. Enable Stencil Test is a new option in materials as of 4.23 Confirmed with OpenGL 3.1 + 2 and Vulkan on Pixel XL Also Crashes on iOS ...

Disabled Skeletal Mesh Sections cause Shadow Ray Tracing Flicker

UE - Rendering - Graphics Features - Ray Tracing - Dec 12, 2025

If a skeletal mesh has a section disabled the ray traced shadow will flicker when the camera or itself moves. Previously in 5.6.0 no raytraced shadow would appear if a section was disabled. This wa ...

Crash when quick binding a function in a class that extends LevelSequenceDirector

UE - Anim - Sequencer - Sep 16, 2020

The purpose was to create a Level Sequence Director inheritance class so that the same event could be reused in multiple sequencers. Attempting to quick-bind this base Level Sequence Director event ...

Camera attached to a Spring Arm jitters when put at a +90 or -90 degree angle on the Y axis.

UE - Gameplay - Nov 18, 2016

When a camera attached to a spring arm is turned at a +90 or -90 degree angle in the Y Axis (can't go any further) and turned, it can jitter and cause visual issues. Note: This occurs in the base ...

Crash editor when open the level sequencer after updated 4.20

UE - Anim - Sequencer - Jan 8, 2019

When migrating from the version before 4.20 to the version after 4.20, opening the level sequencer will crash. I think that there is a problem with conversion from SnapTimeInterval (FixedFrameInterv ...