Unreal Engine Issues
Unreal Engine Issues
Crash in FMovieSceneNumericVariant::Set when loading a Level Sequence with Custom Time Warp on Android
UE - CAPT - Sequencer - Aug 14, 2026On Android, loading a Level Sequence fatals in the async loading thread: Assertion failed: (NewValue & ~PAYLOAD_Bits) == 0 MovieSceneNumericVariant.cpp:133 Unable to store a pointer outside of a ...
Controller Mapping/Unmapping on some platforms is not ideal for local multiplayer
UE - Gameplay - Input - Nov 19, 2025[Link Removed] The workaround is as I posted in the UDN, to override the viewport client or to make a custom slate input mapping to change this behavior. But, there is a bug with that unmapping/l ...
[AI] WP Dynamic navmesh fails to rebuild tiles with actors that are loaded but not part of the base navmesh.
UE - Runtime - Character - Feb 18, 2025WP dynamic navmesh does not properly react to actors or navigation modifiers that are loaded in areas that the navmesh has not yet streamed into. Although the actors/modifiers are not part of the ba ...
Interchange GLTF importer truncates skeletal mesh bone influences to 4 per vertex
UE - Editor - Open File Formats - Aug 21, 2026cf https://forums.unrealengine.com/t/interchange-gltf-importer-truncates-skeletal-mesh-bone-influences-to-4-per-vertex/2745391/2 Original message The UE5 Interchange GLTF importer appears to trunc ...
Regarding TObjectPtr performance regression
UE - Core - Systems - Jul 13, 2026This is from the linked EPS case: ============================== When 5.0 first introduced TObjectPtr, the guidance was that it would compile down to raw pointer access in Shipping builds to ensu ...
UNetDriver server-side hitch results in ActorInfo->NextUpdateTime far into future
UE - Networking - Feb 16, 2024A high UWorld::Tick DeltaSeconds (i.e. GameThread hitch) results in a high UNetDriver::TickFlush DeltaSeconds. This DeltaSeconds can high (many seconds) if the hitch is long. This value then affects ...
The Remove-On-Break feature, set on Fracture Mode on Geometry Collections, stops shrinking and shows strange behaviors
UE - Runtime - Deformable - Oct 15, 2024The Remove-On-Break (ROB) feature, set on Fracture Mode on Geometry Collections (GC), was supposed to make the particle shrink until it vanishes. When the GC goes to sleep the shrinking stops and sh ...
A GeometryCollection that was broken and is going through shrinking will reset the size of its particles if a second level is broken
UE - Runtime - Deformable - Oct 18, 2024Might relate to issue [Link Removed] In Progress - "The Remove-On-Break feature, set on Fracture Mode on Geometry Collectio ...
Calling BodyInstance.UpdateBodyScale displays erratic behaviors and does not update the rendering scale
UE - Runtime - Simulation - Nov 22, 2024Calling BodyInstance.UpdateBodyScale displays erratic behaviors and does not update the rendering scale. The licensee has reported and presented a repro project that displays the erratic behavior of ...
Crash caused by a race condition in Nanite::DispatchBasePass()
UE - Rendering - Graphics Features - Nanite - Feb 25, 2026Nanite::BuildShadingCommands() launches two asynchronous tasks: ShadingCommands.SetupTask ShadingCommands.BuildCommandsTask BuildCommandsTask is responsible for modifying ShadingCommands.Commands ...