Editor Crashes on Opening After Deriving C++ Class from Another Class

UE - Foundation - Cpp Tools - Hot Reload - Sep 13, 2017

After deriving a C++ class from another class and then closing the editor, the project will crash when reopened. This crash will continue until the project files are regenerated and the project is r ...

VC Runtime not in UnrealLightmass temp directory; causing lightmass build errors

UE - Foundation - Cpp Tools - UnrealBuildTool - Oct 14, 2015

A 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, 2019

The 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, 2021

See 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 ...

[VR] Camera attached to non-root scene component in BP will sink into floor after Reset to Floor Origin

UE - Platform - XR - Aug 12, 2016

When 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 Text Widget BP as "Widget Class" in Actor Class BP and compiling multiple times, changes Text visibility in Viewport

UE - Editor - UI Systems - Sep 15, 2017

Adding a new Text Widget Blueprint as a Widget Class to a new Actor Class Blueprint changes the visibility of the Text in the Viewport when compiling the Widget Blueprint multiple times. Regressio ...

Crash in FUniformExpressionSet::FillUniformBuffer trying access deleted UTextureCollection

UE - Rendering Architecture - May 30, 2025

Crash in FUniformExpressionSet::FillUniformBuffer trying access deleted UTextureCollection (Experimental in 5.6). The licensee describes their crash, their analysis, and a proposed fix: This crash ...

Initializing custom Component on Actor in constructor causes odd hierarchy and details panel issues

UE - Gameplay - Blueprint - Feb 19, 2019

When testing with a simple setup, as follows: MySceneComponent has a UProperty(VisibleAnywhere, BlueprintReadOnly) of a USphereComponent pointer, initiated in the Constructor AMyActor has a UProper ...

Focus mode in the Editor does not handle Actors without PrimitiveComponent correctly, treating them as if they were at the origin (0,0,0), skewing the camera placement.

UE - World Creation - Worldbuilding Tools - Nov 18, 2024

Focus mode in the Editor does not handle Actors without PrimitiveComponent correctly, treating them as if they were at the origin (0,0,0), skewing the camera placement. Some Actors like the WorldDat ...

Updating Material does not update platform stats in derived Instance

UE - Rendering Architecture - Materials - Nov 26, 2024

It would seem that updating a material does not update the associated platform stats in a material instance editor, only the parameters. Can workaround by manually invoking shader compile in the ma ...