Unreal Engine Issues
Unreal Engine Issues
Changing MaterialQualityLevel causes a crash due to a ShaderMap mismatch in UniformExpressionCache
UE - Rendering - Architecture - Materials - Nov 26, 2025A crash may occur when changing the MaterialQualitylevel via Scalability due to a race condition. The issue occurs because in ScalabilityCVarsSinkCallback(), when it creates the FGlobalComponentRec ...
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 ...
USkinnedMeshComponent::FindClosestBone does not respect bRequirePhysicsAsset parameter
OLD - Anim - Mar 20, 2017A licensee has reported that the USkinnedMeshComponent::FindClosestBone function does not respect the bRequiresPhysicsAsset parameter, resulting in the bone returning bones that are not part of the ...
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 ...
"ensureAsRuntimeWarning condition failed" when running Snapshot Pose with no assigned skeletal mesh
UE - Gameplay - Blueprint - Jul 7, 2017ensureAsRuntimeWarning occurs when the user use Snapshot Pose with a skeletal mesh component that doesn't have a skeletal mesh assigned to it:LogScript: Error: E:\Release\Engine\Source\Runtime\Engin ...
[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 ...
Soft Object unloads after some time when stored in a Blackboard
UE - AI - Mar 11, 2020When loading a Soft Object and directly placing the loaded Object into a Blackboard, after about 2 minutes the Object will unload and become null inside the Blackboard. This issue only occurs in a p ...
[AI] ZoneShapes visualization does not reset after selecting another actor
UE - AI - Jul 26, 2023ZoneShapes do not reset visuals when being de-selected and re-selected. The last piece of the zone shape to be selected will still show as selected when the shape is re-selected, but using the edito ...
Crash in RHIBreadcrumbs during loading of Bundled PSO Cache if capturing an Insights trace on Win64 Development
UE - Rendering - Architecture - RHI - Feb 17, 2025When compiling a PSO, RHI Breadcrumbs can be fed a bad FRHIBreadcrumbNode, resulting in reading random memory and crashing during the recursive node iteration. This only happens when tracing. The i ...
Crash occur package application which set the StringTable
UE - Foundation - Core - Mar 14, 2019Crash occur the packaging application which has the title referencing StringTablem. When lunch the application with editor and standalone, it's not crash. It' not occur 4.20, and crash with 4.21 and ...