Unreal Engine Issues
Unreal Engine Issues
Materials Added to an FBX Will Not Be Added When Reimporting
Tools - Oct 25, 2018Adding a material to an FBX with a Multi/Sub-object material, then reimporting the FBX will not import the new material. The material element will be added to the mesh but the material applied will ...
Crash: Unhandled exception UE4Editor_Renderer!FMobileBasePassMeshProcessor::Process
UE - Graphics Features - Mar 14, 2019HUD can cause a crash when used with Mobile. "When running from visual studio exception happens here: https://github.com/EpicGames/UnrealEngine/blob/4.22/Engine/Source/Runtime/Renderer/Private/Mobi ...
Disabling DFAO prevents landscape from contributing to Lumen scene
UE - Graphics Features - Lumen - Oct 10, 2023From licensee: We disabled DFAO on our project (using r.DistanceFieldAO 0) to replace it with Lumen occlusion, as the combination of both was creating dark blobs under bushes and grass. However, we ...
Iris - large fast arrays serialize multiple elements when only one is dirtied
UE - Networking - Iris - Apr 8, 2025This seems to be a result of how the changemask is handled for fast arrays. Because the changemask is a fixed set of bits (defined by IrisFastArrayChangeMaskBits), a single bit can represent multipl ...
[Mobile/Forward Rendering] PlanarReflection does not work when the reflection plane faces certain directions
UE - Platform - Mobile - Sep 24, 2025Note: This repros on 4.27 and all 5.x versions. When using the mobile renderer and/or forward shading, Planar Reflection will simply not work if the reflection plane normal has components that add ...
Playing sequences in reverse snaps after sequence has first ran
UE - Anim - Sequencer - Dec 29, 2016I first came across this bug when I was working with Actor Sequences and noticed that the door I had opening would snap back when I tried to close it. Later I discovered that the issue was with play ...
Collapsed component hierarchy expands when placing component in Widget Hierarchy panel
UE - Editor - UI Systems - May 17, 2017A collapsed component hierarchy expands when placing a component in Widget Hierarchy panel. This issue seems similar in nature to [Link Removed], but the test case for this issue id different, and f ...
[CrashReport] UArrayProperty::DestroyValueInternal
UE - Gameplay - Blueprint - Sep 14, 2017This is a somewhat common crash that has affected multiple users in 4.17. User Descriptionstried to compile a blueprint after changing blueprint interface function definitions. Source Code 121 ...
SceneCaptureComponent2D 'Primitive Render Mode' Always Selects Legacy Option
UE - Graphics Features - Nov 9, 2017When using SceneCapture2D and trying to edit the "Primitive Render Mode" (found in Details panel, Scene Capture) you can select the "Render Scene Primitives (Legacy)" and the "Use ShowOnly List" opt ...
Geometry Pen Tool Duplicates Bushes On Grid Size 1 & 5
UE - LD & Modeling - Modeling Tools - BSP - Mar 7, 2018There is an issue occurring when creating brushes with the pen tool at grid size 5 where verticles or the brush shape itself seems to be doubled. This issue also occurs if the grid size is 1, though ...