Unreal Engine Issues
Unreal Engine Issues
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 - Core - Cpp Tools - Automation Tool Framework - Dec 7, 2022Repro 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 ...
OnMovieClipFinished returns the incorrect movie name
Tools - Jun 29, 2017When OnMovieClipFinished is called, it will return the name of the movie clip that is about to be played rather than the clip that had just finished. Regression: Yes This did not occur in 4.15.3 B ...
CreateWidget node keeps reference to created widget on output pin
UE - Gameplay - Blueprint - Oct 17, 2017There was an issue in 4.16 (fixed in CL# 3437205) in which blueprint output pins would hold on to object references until the blueprint was destroyed. It appears that an additional fix may need to b ...
Substrate Unlit editor view mode renders black with Blendable GBuffer
UE - Rendering - Features - Shading Models - Mar 18, 2026When 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 ...
[CrashReport] Fatal error: Cast of nullptr to Actor failed - UE4Editor_CoreUObject!CastLogError()
Tools - Jul 19, 2017This is a common crash affecting users in 4.16, and has been occurring since at least 4.14. It has affected more than 400 unique users, unfortunately they have provided little information. User Des ...
[CrashReport] UE4Editor_Engine!FHLSLMaterialTranslator::GetParameterUniformExpression() [hlslmaterialtranslator.h:1671]
UE - Graphics Features - May 25, 2017This is a top trending crash in the 4.16 release. This may be a regression from 4.15. Additional information is currently unknown. Users have not provided any details. ...
Editor crash when calling SGridPanel::SetRowFill
Tools - Aug 22, 2017Calling SGridPanel::SetRowFill on an actor's BeginPlay causes the editor to crash with the callstack provided The reporter mentioned SetRowFill uses if() statement where SetColumnFill uses while() ...
Disabled Skeletal Mesh Sections cause Shadow Ray Tracing Flicker
UE - Rendering - Features - Ray Tracing - Dec 12, 2025If 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 editor when open the level sequencer after updated 4.20
UE - Anim - Sequencer - Jan 8, 2019When 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 ...
PCG crash when using Attribute Remove Duplicates on partitioned data if one of those sets of data is empty
UE - Graphics Tools - PCG - Graph - Jul 3, 2025Context: In PCG, the Attribute Remove Duplicates node can be used to remove duplicate attributes from an array. Problem: The licensee has observed that using the Attribute Remove Duplicates node ...