Unreal Engine Issues
Unreal Engine Issues
ActorComponents registered with wrong world from UWorldPartition::ApplyRuntimeCellsTransformerStack
UE - World Creation - Worldbuilding Tools - World Partition - Dec 17, 2025There is a risk of actor components registering with the wrong world when reconstructed from UWorldPartition::ApplyRuntimeCellsTransformerStack. The repro case is arguably a bad usage, but it was th ...
A chaos vehicle that moves at very high speeds with CCD enabled on the vehicle sometimes has a collision response that is abnormal where the vehicle loses a significant amount of speed when colliding with dynamic objects configured as One Way Interaction
UE - Simulation - Gameplay - Dec 16, 2025Context: Continuous Collision Detection (CCD) is being used on a Chaos Vehicle to avoid tunneling issues with certain surfaces as it prevents any missed collisions between fast moving particles and ...
[AI] StateTree fails to compile after copy/pasting a state with a task that binds to required event on the state's enter conditions
UE - AI - StateTree - Dec 14, 2025StateTree appears to keep an incorrect reference to the event from the source tree rather than re-establishing the property binding to the new tree's event. This happens when copy/paste of the state ...
VirtualTextureStreamingPriority cannot be set per TextureLODGroup
UE - Rendering Architecture - Dec 11, 2025It is currently not possible to set a VirtualTextureStreamingPriority via the TextureLodGroups that are defined in a device profile. ...
[ALT] - UE56 Editor launched with -AsyncLoadingThread will trigger MTAccess
UE - DEET - EditorLoader - Dec 10, 2025When launching the editor with the -AsyncLoadingThread command, the engine uses an asynchronous thread to load and instantiate UObjects. At this point, if the instantiated UObject contains an FData ...
Convex hull generation fails when first 3 verts are colinear
UE - Simulation - Core - Dec 9, 2025The licensee identified a number of cases where loading assets will trigger convex hull generation warnings:If the first 3 verts in the set are colinear (in which case IsPlanarShape() returns true b ...
Texture Streaming can randomly streams in all Mips, causing large memory spikes
UE - Rendering Architecture - RHI - Dec 5, 2025A possible race condition allows texture instance views to read uninitialized bounds, causing either garbage or zero screen size values to be returned by FRenderAssetInstanceAsyncView::GetRenderAsse ...
Drag and Drop fails in Standalone and Packaged builds when WidgetComponent’s Widget is set at runtime
UE - Editor - UI Systems - Dec 4, 2025When a UWidgetComponent has its widget assigned dynamically at runtime using CreateWidget and SetWidget, drag & drop operations fail in Standalone Game and packaged/game builds, while working correc ...
Issue with Niagara emitter inheritance
UE - Niagara - Dec 4, 2025Modules in the particle spawn stage get unlocked and lose inheritance after changing the inherited emitter's interpolated spawn mode to "No Interpolation" then resetting. ...
Morph target is not applied on the first frame in Level Sequence
UE - Anim - Rigging - Dec 4, 2025When a skeletal mesh with morph targets spawns in the sequence, the morph is not reflected in the first frame. In the ProcessStage_SkinCache call of SkeletalMesh, MorphVertexBuffer->SectionIds is ...