Unreal Engine Issues
Unreal Engine Issues
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 ...
Undo and ConstructionScript break the AttachChildren array
UE - Gameplay - Components - Nov 14, 2019Undo fills AttachChildren array with null by the undo serializer. After that, a construction script tries to remove child components from parent component's AttachChildren but it can't find its poi ...
FBX imported skeletal mesh has incorrect axis directions
UE - Editor - Content Pipeline - Import and Export - Aug 20, 2019The axis the FBX is imported with has been inversed from prior versions. See attached screenshots. This causes issues specifically with vehicles, where the movement is happening into the forward dir ...
Upgrading project results in loss of game input
UE - Gameplay - Input - Jan 7, 2020Upgrading a marketplace creator's project to engine version 4.23.1 and above results in loss of (previously) working functionality with game input. ProjectDownload: [Link Removed] Tested in: 4.2 ...
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 ...
Adding Niagara system to a projectile causes a crash
UE - Niagara - Jul 29, 2019Adding a Niagara system to a BP_Projectile in a C++ First Person Project and then restarting it causes the editor to crash. Tested in 4.21.2 (CL - 4753647), 4.22.3 (CL - 7053647), 4.23 (CL - 744 ...
Initializing custom Component on Actor in constructor causes odd hierarchy and details panel issues
UE - Gameplay - Blueprint - Feb 19, 2019When 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, 2024Focus 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 ...