Unreal Engine Issues
Unreal Engine Issues
Disabled Skeletal Mesh Sections cause Shadow Ray Tracing Flicker
UE - Graphics Features - Ray Tracing - Dec 12, 2025If a skeletal mesh has a section disabled the ray traced shadow will flicker when the camera or itself moves. Previously in 5.6.0 no raytraced shadow would appear if a section was disabled. This wa ...
[3ds max] Some geometry will display in all black in Path Tracer renders
UE - Editor - Content Pipeline - Datasmith - Exporters - Dec 12, 2025Reported in SF [Link Removed] Some geometry from 3ds Max will display as all black when viewed in Path Tracer rendering. This effect is visible in both UE and Twinmotion. This was tested with Data ...
Skeletal Meshes created in Unreal with only a root bone do not export correctly
UE - Editor - Content Pipeline - Import and Export - Nov 17, 2025WorldPartitionConvertCommandlet hits an assert when converting a persistent level that contains a sub-level with a landscape
UE - World Creation - Worldbuilding Tools - Nov 7, 2025Context: The Window tab allows a user to open the Levels window in order to add a sub-level to a persistent level. For Unreal Engine 5.0 and beyond, World Partition has made the Levels window obsole ...
Landscape Splines in Partially Loaded World Partition Levels Can Cause Nanite Landscape Invalidation
UE - Graphics Tools - Terrain - Nov 7, 2025Certain placements of landscape splines in world partition levels can cause Nanite landscape proxies to invalidate, and switch back to their non-nanite version. This happens when specific regions of ...
net.ReplicateCustomDeltaPropertiesInRepIndexOrder is not respect the cvar for the custom properties
UE - Networking - Nov 5, 2025In our project do not use iris and we use a subclass UExtendAbilitySystemComponent derived from UAbilitySystemComponent. In this subclass, there is a FastArray member variable named ExtendActivatabl ...
Static Mesh Contact Shadows still render when all LOD sections have Cast Shadows dissabled
UE - Graphics Features - Oct 30, 2025When the cast shadow checkbox is disabled for all sections that make up a static mesh the main shadow is no longer rendered but the contact shadow does not respect the instruction to disable shadows ...
Cloth Asset - Crash when importing morph targets into clothing
UE - Simulation - Visual - Oct 20, 2025The sim morph import has been broken after a change to make it work for cooked assets. Ticking the Import Sim Morph Targets checkbox crashes as soon as a skeletal mesh with morph target is specifie ...
Light Leak Issue in Modular Buildings (Lumen HZBTraversal)
UE - Graphics Features - Lumen - Oct 14, 2025Starting in Unreal Engine 5.6, disabling "r.Lumen.ScreenProbeGather.ScreenTraces.HZBTraversal" can lead to light leaking between adjacent or overlapping meshes. Also tested on Release-5.6, CL: 4523 ...
Material Instance Platform Stats don't update when Material Layer parameters are changed
UE - Rendering Architecture - Materials - Oct 14, 2025The instruction count appears to update properly if the whole asset editor is closed and reopened. ...