Unreal Engine Issues
Unreal Engine Issues
Incorrect Lumen Scene direct lighting when objects behind masked landscape
UE - Graphics Features - Lumen - Oct 5, 2025When objects are placed behind or beneath a masked landscape and r.Lumen.HardwareRayTracing.SurfaceCacheAlphaMasking is enabled, the direct light evaluation is incorrect. There are two workarounds, ...
Crash when saving a Data Table that is referencing itself in a Data Table Row Handle
Tools - Feb 23, 2017Crash when saving a Data Table that is referencing itself in a Data Table Row Handle. Reopening the project also causes a crash. *Regression: Yes This was fixed and working in 4.13-3037605 This i ...
Simulated physics bodies not working properly with BP Move Component To node
UE - Simulation - Physics - Jun 5, 2015This issue may reference [Link Removed] which was recently fixed with 4.9 CL-2553675. When using the MoveComponentTo node physics do not work properly compared to other methods to move a component ...
BulkData Async loading remains in memory
UE - Foundation - Core - Oct 26, 2016Gil's new loading path may already walk away from this issue. But here's some thing I tested locally if we want to fix this. A simple way to fix is to simply add BulkDataAsync.Deallocate(); ResetA ...
[CrashReport] UE4Editor_UMG!UWidget::GetParent() [widget.cpp:610]
UE - Editor - UI Systems - Oct 19, 2017This is a trending crash coming out of the 4.18 previews and 4.18.0. Users have not provided any descriptions of their actions when the crash occurred. Source Context 597 void UWidget::SetA ...
VC Runtime not in UnrealLightmass temp directory; causing lightmass build errors
UE - Foundation - Cpp Tools - UnrealBuildTool - Oct 14, 2015A Redistribute file for VS 2015 is needed to build lightmass, but this is not currently included with the engine. If a user does not have VS 2015 installed, lightmass will fail with this error: Un ...
Pasted material function nodes lose their connections
UE - Rendering Architecture - Materials - Dec 3, 2019The fix for [Link Removed] caused a regression where links to material nodes no longer carry over when a group of nodes is copied and pasted ~ User submitted Image and repro steps appended. I conf ...
Different instanced materials are seen as the same material due to GUID
UE - Graphics Features - Jun 3, 2021See licensee description of the issue: The problem appears when I have two instanced materials with the same number of parameters. I've noticed that ShaderMapId has MaterialLayersParameterIDs where ...
Invalid GUIDs on new material instance parameters cause overrides to break on base param rename
UE - Rendering Architecture - Materials - Sep 3, 2025When a parameter value is assigned on a newly created material instance (constant or dynamic) using Set***ParameterValueInternal, the parameter’s ExpressionGUID is left invalid (0,0,0,0). Parameter ...
[VR] Camera attached to non-root scene component in BP will sink into floor after Reset to Floor Origin
UE - Platform - XR - Aug 12, 2016When a project is first created following the Setting up UE4 to work with SteamVR docs, the Vive camera works correctly and will display at the correct height. However, if at any point during develo ...