Unreal Engine Issues
Unreal Engine Issues
StaticMesh reimport not preserving support for physical material masks
UE - Simulation - Core - Feb 10, 2026Client has a workflow issue with the reimport pipeline: UStaticMesh::bSupportPhysicalMaterialMasks should be copied over to UBodySetup::bSupportUVsAndFaceRemap before it takes effect for raycasts, ...
DynamicMaterialParameters Niagara module resets write flags on emitter update
UE - Niagara - Feb 4, 2026When using the DynamicMaterialParameters Niagara module in UE 5.6, 5.7, and UE5-Main (CL 50298778), updating an emitter causes Boolean values, such as Index0Float0Write, to reset to default values, ...
Tooltips not appearing in Editor when hovering over assets due to Slate Cursor Move settings
UE - Editor - UI Systems - Slate - Feb 3, 2026User noticed that when Slate.EnableSyntheticCursorMoves is set to false the editor UI tooltips no longer display. As noted by the user, modifying Slate.CursorSignificantMoveDetectionThreshold to at ...
Material Analyzer misreports static params for Material Layers
UE - Rendering - Architecture - Materials - Jan 20, 2026When analyzing materials that use Material Layers, Material Analyzer reports that multiple Material Instances “share the same static parameter array” and therefore recommends reparenting so that onl ...
Optimize closing the Material Editor and Material Instance Editor
UE - Rendering - Architecture - Materials - Jan 15, 2026[Link Removed] We always need to build texture data which requires building debug view mode shaders to do some rendering to get texture densities. Can we find another way to do this? Can we at le ...
Detaching a component may not be replicated to clients
UE - Networking - Jan 13, 2026Because the archetype for scene/static mesh components has a null value for AttachParent, there are some situations where changes to a replicated component's AttachParent are not replicated to clien ...
bWeldSimulatedBodies not replicated with attachment
UE - Simulation - Core - Jan 13, 2026The bWeldSimulatedBodies attachment parameter is not replicated to clients, both in USceneComponent's attachment replication handling and in AActor's FRepAttachment struct. If AttachToComponent is c ...
If a child blueprint class has an Instanced/EditInlineNew object property, that property will always be detected as changed by the property editor (i.e. it will show a "Revert" arrow on that property), even if its properties are identical to the parent.
UE - Framework - Blueprint Editor - Dec 17, 2025Context: Blueprint classes can use Instanced/EditInlineNew object property specifiers to create and edit subobjects directly in the editor. Problem: If a child blueprint class has an Instanced/Edit ...
Iris - BeginPlay not called on client for statically placed, low-priority replicated actor
UE - Networking - Iris - Dec 11, 2025On the client, NotifyBeginPlay is triggered via AGameStateBase::OnRep_ReplicatedHasBegunPlay. However, if a replicated actor is waiting on its initial replicated state to be received and applied (bA ...
Replicated timeline may not call Finished event on client
UE - Networking - Dec 9, 2025It seems this can happen if the timeline component on the client receives an update from the server for the final position of the timeline, causing it to be set as no longer playing before it has a ...