Unreal Engine Issues
Unreal Engine Issues
ChaosCacheManager is not recording the Observed GeometryCollections NotifyBreak states between level loading and will default to false if changed from Record to Play
UE - Runtime - Simulation - Mar 28, 2025ChaosCacheManager (CCM) is not recording the Observed GeometryCollections (GC) NotifyBreak states between level loading and will default to false if changed from Record to Play. AChaosCacheManager ...
ChaosCacheManager is not reproducing Collision Events the second time you Record and Play
UE - Runtime - Simulation - Mar 28, 2025ChaosCacheManager (CCM) is not reproducing Collision events the second time (and onwards) we record a Geometry Collection (GC) breaking session. Particles set to track Collision Events correctly fol ...
Crash When Typing a Node Comment and Hovering Over the Alignment Option
Tools - Apr 5, 2016Error message: Assertion failed: ParentIndex != INDEX_NONE [Link Removed] [Line: 512] Source Context: 499 } 500 501 return Menu; 502 } 503 504 ...
Editor ensure in USceneComponent::OnComponentDestroyed during Blueprint compilation GC
UE - Framework - Components - Jan 15, 2026An editor-only ensure can trigger during BP compilation when garbage collection cleans up transient components created as part of component replacement. During recompilation, old component instances ...
[CrashReport] ULevel::GetWorldSettings - UMaterialFunctionThumbnailRenderer::Draw
Tools - Oct 30, 2017This is a common crash that has occurred since at least 4.16. The callstack is nearly identical to [Link Removed], which appears to be fixed in 4.18; and [Link Removed], which has not. The differen ...
Deadlock when running an asset validator commandlet with async skeletalmesh build
UE - Editor - Open File Formats - Asset Migration - Mar 10, 2023[External Code] UnrealEditor-Core.dll!FEventWin::Wait(unsigned int WaitTime, const bool bIgnoreThreadIdleStats) Line 1515 C++ UnrealEditor-Engine.dll!FAsyncTaskBase::WaitCompletionWithTimeout( ...
[CrashReport] Assertion failed: !bIsReentrant - UE4Editor-UnrealEd.dylib!SaveWorld()
UE - Platform - Apple - Jul 27, 2017This is a common crash on Mac in 4.16 and has occurred since at least 4.14. User DescriptionsI added a character to a blank map and tried to save it. Callstack from LogLogEditorViewport: Clicking ...
Niagara Scalability Crash When Processing Significance
UE - Rendering - Architecture - Niagara - Jun 4, 2025Method FNiagaraScalabilityManager::ProcessSignificance() iterates on indices from Context.SignificanceIndices and uses them to access the State and ManagedComponents arrays. It can then decide to cr ...
MovieRender Pipeline Skips Output Frames during GC
UE - Anim - Sequencer - Jun 8, 2020This is being seen in the wild... can release a temporary fix until 4.26 when we can change the headers and fix it for real. ...
Chaos Mover crash in standalone editor client
UE - Runtime - Character - Aug 18, 2026When using the Chaos Mover with resimulation enabled, standalone editor processes running as a client will crash around 80% of the time upon startup. ...