Unreal Engine Issues
Unreal Engine Issues
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 ...
Timeline functions do not work inside of Blueprint functions
UE - Gameplay - Blueprint - Dec 20, 2014I could not repro their issue in main. They supposedly recently upgraded to 4.5. I was wondering if you could divide an conquer, and figure out when we fixed this. **EDIT** Was able to repro in mai ...
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 ...
Adding a custom plugin to a code project that is in the root location of a drive will result in an error stating that the plugin was found in two locations
UE - Foundation - Cpp Tools - Plugin System - Nov 25, 2016Creating a new custom plugin in the root location of a drive results in the project being unable to open or build. An error message appears that states that the plugin was found in two locations, an ...
Crash on play if a BP uses a ClearInstances node followed by an AddInstance node
UE - Graphics Features - Jul 21, 2017Crash on play if a BP manipulates a InstancedStaticMeshComponent by using a ClearInstances node followed by an AddInstance node. This is a blocker for the licensee. This is a regression: Working ...
Crash in FUniformExpressionSet::FillUniformBuffer trying access deleted UTextureCollection
UE - Rendering Architecture - May 30, 2025Crash in FUniformExpressionSet::FillUniformBuffer trying access deleted UTextureCollection (Experimental in 5.6). The licensee describes their crash, their analysis, and a proposed fix: This crash ...
BlueprintNativeEvents are not overridden correctly with multiple levels of inheritance
UE - Gameplay - Blueprint - Mar 9, 2017When overriding a BlueprintNativeFunction in a child class, if the inheritance is multiple levels deep, the override does not work correctly. As shown in the reproduction steps, this the example to ...