Unreal Engine Issues
Unreal Engine Issues
Water: Data race calling MarkOwningWaterZoneForRebuild from FWaterBodyInfoMeshSceneProxy constructor during concurrent render state creation
UE - Graphics Tools - Terrain - Water - Oct 14, 2026Summary The FWaterBodyInfoMeshSceneProxy constructor (WaterBodyInfoMeshComponent.cpp) calls UWaterBodyComponent::MarkOwningWaterZoneForRebuild(). The proxy is created from CreateRenderState_Concurren ...
FMultiReaderSingleWriterGT isn't thread safe
UE - Foundation - Core - May 17, 2016From https://udn.unrealengine.com/questions/292741/fmultireadersinglewritergt-isnt-thread-safe.html: I've found that FMultiReaderSingleWriterGT has at least 2 bugs: The one that caused a deadlock ...
Lags in animation when set leader pose component is used
UE - Rendering - Architecture - Aug 2, 2023https://udn.unrealengine.com/s/question/0D54z00009UJv5HCAT/lags-in-animation-when-set-leader-pose-component-is-used From licensee: "USkinnedMeshComponents have the option to double-buffer their bo ...
Montage Editor calls NotifyEnds of AnimNotifyState even when paused
UE - Runtime - Animation - Oct 13, 2023In the Animation Montage Editor, NotifyEnd is unexpectedly called when a time marker is in the middle of an AnimNotifyState and the animation preview gets paused. Because the Animation Montage Edito ...
Launching multiple Editor processes in UE 5.5 can throw warnings due to USD Core plugin initialization
zComponent - Archive - Apr 23, 2025Launching multiple Editor processes at the same time with the USD Core plugin enabled can cause warnings to be logged like the following:LogUsd: Warning: Failed to update LibraryPath for USD plugInf ...
BlendSpace Loop Boundary Produces Inconsistent Sync Marker Data andTriggers an AnimSequence Follower Assertion
UE - Runtime - Animation - Jul 22, 2026Summary In UE 5.7.4, when a looping BlendSpace with Match Sync Phases enabled plays as a SyncGroup Leader and crosses its loop boundary during a transition to an external AnimSequenceFollower in th ...
[CrashReport] UE4Editor_Engine!FAnimCurveBase::SetCurveTypeFlag() [animcurvetypes.cpp:18]
OLD - Anim - Jun 13, 2016This Jira was created from CrashReports submitted by the public due to the high number of occurrences. Descriptions from users are provided below. Error message: Access violation - code c0000005 ( ...
Target Rotation of Physics Handle doesn't register and can't be manipulated on tick
UE - Gameplay - May 26, 2016Target Rotation of Physics Handle doesn't register and can't be manipulated on tick User Description: I mentioned some versions before that rotation of Physics Handles is broken and now it is even ...
Static Mesh approximate size can be inconsistent between Content Browser and Static Mesh Editor
Tools - May 3, 2017The approximate size for a Static Mesh that is shown in the tooltip from hovering over a Static Mesh in the Content Browser and the approximate size shown in the Static Mesh Editor can be inconsiste ...
Landscape BP Brushes in WP map causes changelist validation to fail
UE - Engine Scaling - Streaming - World Partition - May 13, 2022Using a Landscape BP brush in a WP map causes SCC validation to fail: [2022.05.13-09.04.47:880][473]SourceControl: Error: Changelist validation failed! [2022.05.13-09.04.47:881][473]SourceControl: ...