Unreal Engine Issues
Unreal Engine Issues
BlendSpace DeltaTimeRecord.Delta can incorrectly be set to zero
UE - Anim - Runtime - Apr 19, 2024It's possible for blendspaces to end up with an invalid delta time record because of how UBlendSpace::TickAssetPlayer modifies the time record. This only seems to happen with specific settings:Axis ...
Tick functions are skipped on the first frame in package build and standalone PIE
UE - Gameplay - May 19, 2025It's reported that all Tick functions are skipped on the first frame when running in packaged builds and standalone PIE. This is because both TickVisitedGFrameCounter and GFrameCounter are initializ ...
Crash on adding new element to ChaosCacheCollection if ChaosCacheCollection is open in editor
UE - Simulation - Physics - Destruction - Dec 11, 2020More ways to reproduce:In Chaos Cache Collection Editor press Add Element button (no matter when you will do this step)If in Step13 from Steps to reproduce you won't place Chaos Cache Collection Edi ...
Cook Determinism - Construction Scripts and ChildActorComponent issues with DiffCooks
UE - Framework - Components - Jul 26, 2024To step through the issue, in the -DiffOnly cook add a breakpoint to UChildActorComponent::OnRegister and UChildActorComponent::OnUnregister. It should hit 4 times:Once when LoadPackage loads the ma ...
DynamicEntryBox with EntryBoxType Radial is stacking Entries if SectorCentralAngle is multiple of 360.0f and DistributeItemsEvenly is enabled
UE - Editor - UI Systems - May 27, 2025DynamicEntryBox with EntryBoxType Radial is stacking Entries if SectorCentralAngle is multiple of 360.0f and DistributeItemsEvenly is enabled. The licensee has provided an analysis: On void SRadia ...
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 ...
ShooterGame references images in slate from a folder that does not exist
Docs - Samples - Jul 8, 2015A user has found that there are a few lines of code inside of shooter game that references a folder that does not exist. The lines of code below are the lines of code that reference images in an ima ...
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 - Anim - Gameplay - 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
UE - Editor - Content Pipeline - USD - 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 ...