ChaosCacheManager is not reproducing Collision Events the second time you Record and Play

UE - Simulation - Physics - Mar 28, 2025

ChaosCacheManager (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 After setting Default Text Material Opaque as a Dynamic Material Instance in the construction script

Tools - Apr 19, 2016

This Jira was created from CrashReports submitted by the public due to the high number of occurrences. Error message: Fatal error: [Link Removed] [Line: 1829] /Game/ThirdPersonBP/Maps/ThirdPersonE ...

Crash in UEditorEngine::CheckForWorldGCLeaks

Tools - Feb 20, 2017

Error message: Fatal error: [Link Removed] [Line: 1959] /Game/FirstPersonBP/Maps/FirstPersonExampleMap.FirstPersonExampleMap still around trying to load ../../../Engine/Content/Maps/Templates/Templ ...

[CrashReport] UE4Editor-CoreUObject.dylib!UObject::Rename()

UE - Platform - Apple - Sep 14, 2017

This is an infrequent Mac crash that has occurred for a few users in 4.17. Users have not provided any description of their actions when the crash occurred. The callstack has a few similarities to ...

Deadlock when running an asset validator commandlet with async skeletalmesh build

UE - Editor - Content Pipeline - Asset Build - Mar 10, 2023

[External Code]   UnrealEditor-Core.dll!FEventWin::Wait(unsigned int WaitTime, const bool bIgnoreThreadIdleStats) Line 1515 C++   UnrealEditor-Engine.dll!FAsyncTaskBase::WaitCompletionWithTimeout( ...

New VR-Basic level triggers Metal validation layer assertion

UE - Platform - Apple - Mar 16, 2020

This was discovered externally and reported on UDN here: https://udn.unrealengine.com/questions/563268/mac-editor-crash-when-disable-ambient-occlusion.html ...

Deadlock in UPhysicalAnimationComponent::UpdatePhysicsEngineImp

UE - Simulation - Physics - Sep 13, 2023

Deadlock in Chaos during PIE; the main thread is in USkeletalMeshComponent::HandleExistingParallelEvaluationTask waiting for a task to complete, and a worker thread is running that task and is in US ...

Niagara Scalability Crash When Processing Significance

UE - Niagara - Jun 4, 2025

Method FNiagaraScalabilityManager::ProcessSignificance() iterates on indices from Context.SignificanceIndices and uses them to access the State and ManagedComponents arrays. It can then decide to cr ...

Constraint axes are not visible in Physics Asset editor viewport

OLD - Anim - Jul 10, 2017

This is a regression from 4.16 as I was not able to repro this issue in //UE4/Release-4.16 at CL 3514769. ...

Unable to create installed build with iOS support from PC

UE - Foundation - Core - May 3, 2017

Attempting to build a local binary engine from a source engine will fail when iOS support is enabled in the setup process. Command line argument (ran from Engine/Build/BatchFiles folder location): ...