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 ...

ALT-Drag a non-DBuffer Decal will Crash the Engine

UE - Graphics Features - Jun 11, 2015

When you ALT-Drag a Decal that is not using the Dbuffer settings, the Engine will crash. The issue is not reproducible in Main Promotable-CL-2581018 This is a regression. Worked in 4.7.6, broken ...

[CrashReport] UE4Editor_CoreUObject!FCompressedChunk::FCompressedChunk()

UE - Foundation - Core - Jul 24, 2017

This is a common crash affecting users in 4.16 and the 4.17 Previews. The two descriptions provided by users say their crash occurred after updating their project from 4.13. User DescriptionsUpgra ...

Spline Mesh Component doesn't render if two spline points are directly above and below each other

Tools - Dec 1, 2017

Spline Mesh Component doesn't render if two spline points are placed exactly above and below each other. If they are offset by any value other than 0.0, the Spline Mesh component will be rendered as ...

Attached Project Crashes When Attempting to Open Blueprint

UE - Gameplay - Blueprint - Nov 11, 2015

The project in question: [Link Removed] The user is experiencing an issue where they've fixed compile errors on their NPC blueprint, and now are unable to open it without experiencing a crash. Righ ...

[CrashReport] UE4Editor_Engine!UAssetImportData::ExtractFilenames() [assetimportdata.cpp:156]

Tools - Sep 7, 2017

This is a common crash affecting users in 4.17 and 4.18. User DescriptionsI wasn't able to get my UCX collision to import. Clicked the yellow "return" arrow next to the asset import settings option ...

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 ...

Dynamic Materials created on level actors through binding actor to sequencer causes missing asset in multiuser and crash in editor

UE - Anim - Sequencer - Apr 1, 2024

[2024.02.24-00.44.16:412][ 0]LogOutputDevice: Error: === Handled ensure: === [2024.02.24-00.44.16:412][ 0]LogOutputDevice: Error: [2024.02.24-00.44.16:412][ 0]LogOutputDevice: Error: Ensure condit ...

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 ...