Unreal Engine Issues
Unreal Engine Issues
Complex collision mesh might lose its collision in the editor
UE - LD & Modeling - Modeling Tools - Mesh Editing - Feb 18, 2020This is affected by loading order. In the case, display mesh was loaded firstly and try to build collision mesh form complex collision mesh asset. But the collision mesh didn't finished to make Ren ...
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 ...
Mouse Not Functioning Correctly with Multiple Displays Connected to Mac
UE - Platform - Apple - Apr 24, 2015When using mutliple monitors connected to a Mac the mouse behavior does not function well. Attempting to navigate and drag windows to and from individual displays proves difficult. The user reporti ...
Using the Editor in Fullscreen mode on Linux causes it to freeze and occasionally lock up the computer
UE - Platform - Linux - May 29, 2019Using the Editor in Fullscreen mode on Linux causes it to freeze and occasionally lock up the computer. This freeze causes the various symptoms described in the Results field. In 4.21.2 (CL-4753647) ...
Large Landscapes cause long PIE start time delays
UE - LD & Modeling - Terrain - Landscape - Jan 29, 2020These delays appear with large Landscapes (for example 8029 x 8029) . The delays only start occurring after the level is saved and reopened. After which PIE start times will be 5 to 15 times longer ...
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 ...
Landscape LOD behaviours is not working as expected (Its Calculation is not based on Sections anymore)
UE - Graphics Tools - Terrain - Landscape - Apr 10, 2024"Components can optionally be divided into either 1 or 4 (2x2) subsections to increase the resolution of the Landscape. These subsections are the base unit of Landscape LOD calculation." From Doc ...
Clothing Data paint doesn't effect visible mesh
UE - Simulation - Physics - Jan 7, 2020Skeletal mesh sections with cloth should have their visible mesh match their simulated mesh and this should be effected by painted values. Any vertices left unpainted(at 0) after the initial paint, ...