Unreal Engine Issues
Unreal Engine Issues
[WorldPartition][CellTransformer] 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 ...
Paper2D: Editor hangs when assigning Sprite Atlas Group to Sprite
UE - Gameplay - Paper2D - Dec 16, 2025In UE 5.3 and later, assigning a Sprite Atlas Group to a UPaperSprite asset can cause the editor to hang and eventually crash. This behavior has been reproduced in 5.3, 5.6, and a recent UE5-main so ...
[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 - Foundation - Core Systems - 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 ...
Virtual texture thumbnails appears brighter (incorrect sRGB/gamma) in content browser after asset is loaded
UE - Editor - Dec 9, 2025This is a regression, it worked correctly up to UE 5.5 but behaves incorrectly in UE 5.6 up to latest. When a regular texture with sRGB enabled is converted to a virtual texture, its thumbnail in t ...
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 ...