Different instanced materials are seen as the same material due to GUID

UE - Rendering - 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 ...

Invalid GUIDs on new material instance parameters cause overrides to break on base param rename

UE - Rendering - Architecture - Materials - Sep 3, 2025

When 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, 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 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, 2016

Creating 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, 2017

Crash 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, 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 ...

BlueprintNativeEvents are not overridden correctly with multiple levels of inheritance

UE - Gameplay - Blueprint - Mar 9, 2017

When 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 ...

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 - Engine Scaling - Streaming - 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 ...