Unreal Engine Issues
Unreal Engine Issues
NormalizePackageNames() should interpret 'exclude developer folders' to also exclude packages in ExternalActors and ExternalObjects
UE - CoreTech - Oct 14, 2022In NormalizePackageNames() (PackageUtilities.cpp), there is a PackageFilter parameter, which can be set to exclude developer packages (NORMALIZE_ExcludeDeveloperPackages). The code only checks the b ...
Placing a section at the end of montage is not properly handled
UE - Anim - Gameplay - Feb 24, 2024Placing a section at the very end of a montage with no duration or animation assigned after it is not properly handled. Normally sections with 0 length are skipped and search continues since they ...
FAnimMontageInstance::SetNextPositionWithEvents can trigger all notifies on a montage/sequence
UE - Runtime - Animation - Jun 24, 2025This issue happens when Sequencer loops a dynamic montage. FAnimMontageInstance::ForcedNextFromPosition is set to 0 and ForcedNextToPosition is effectively the delta time. However, FMontageSubStep ...
Performance slowdown when ray tracing is disabled due to SetResidencyPriority
UE - Rendering - Architecture - RHI - Jul 17, 2025When a game is compiled with ray tracing disabled (D3D12_RHI_RAYTRACING=0) and the GPU the game is running on becomes low on VRAM, frame time is negatively impacted and doesn't recover. The D3D12_RH ...
Landscape Textures Patches issue when using "Texture Backed Render Target" as the Height Patch Source Mode where Landscape patches are not applying properly the first time a level is opened after restart
UE - Graphics Tools - Terrain - Landscape - Oct 6, 2025Context: Landscape patches are components that can be attached to meshes to affect the landscape as the mesh is repositioned. Problem: The problem is that when using "Texture Backed Render Target" ...
Crash when exporting Static Meshes as an FBX (UE4Editor-SlateCore.dll!SWidget::OnQueryShowFocus)
Tools - Sep 21, 2017Possibly related to [Link Removed] ...
Crash on Device when Deploying Mobile Project with Modulated Shadows and Planar Reflections on iOS 9
UE - Platform - Mobile - Jan 6, 2017A crash occurs on iOS when deploying the licensee's project using iOS 9 version. The crash does not occur when deployed to a device using iOS 10 version. They believe the crash to be related to Pl ...
USplineComponent::GetDistanceAlongSplineAtSplineInputKey returns incorrect result when input keys are not sequential
UE - Editor - May 18, 2022USplineComponent::GetDistanceAlongSplineAtInputKey() returns the wrong value when the input keys are not sequential because it interprets the input key argument as the spline point index. Thus if th ...
Electra video playback fails if project or package is under multibyte characters path
UE - Media Framework - Sep 16, 2022The URL parser encodes the input path to a URL-encoded path even if it is local, so if the path contains unicode characters (such as Japanese Kanji ), the media file cannot be read. Following worka ...
C# UHT fails to recognize delegates declared in another class's namespace
UE - Foundation - Cpp Tools - UnrealHeaderTool - Dec 14, 2022Repro Rate: 3/3 This issue occurs in the live build //UE5/Release-5.1 at CL 23058290. This issue has also been regression tested against //UE5/Release-5.0 at CL 20979098 and is confirmed to be a r ...