Non-existing config file loading could cause memory leak

UE - Core - Systems - Oct 19, 2023

The cause of this problem is the Engine has code paths which register a new allocated object to Map without deleting the previous object. In the repro project, whenever hitting Space Bar, the level ...

Regarding TObjectPtr performance regression

UE - Core - Systems - Jul 13, 2026

This 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 ...

Crash while scrolling through language options in Packaging settings

Tools - Jul 21, 2017

This is a trending crash in the 4.17 preview. This is a regression Broken: 4.17.0-3528061 Worked: 4.16.2-3514769 User Descriptionsproject/settings/intern..language. Crashed it just by scrolling t ...

Chaos Trailing Events not exposed to Blueprints and only accessible via Niagara Chaos DI

UE - Runtime - Deformable - Apr 22, 2025

Chaos Trailing Events not exposed to Blueprints and only accessible via Niagara Chaos DI. The licensee noticed that the Trailing event is not available to BPs. It's expected that the same data avail ...

[CrashReport] UE4Editor_Core!FArchiveFileReaderGeneric::InternalPrecache() [filemanagergeneric.cpp:697]

UE - Foundation - Core - Jun 20, 2016

This Jira was created from CrashReports submitted by the public due to the high number of occurrences. Descriptions from users are provided below. Error message: Assertion failed: false [Link Remo ...

[CrashReport] UE4Editor_UnrealEd!TSet<FEditorUndoClient * | SActorDetails::~SActorDetails

Tools - Sep 20, 2017

This is a somewhat common crash coming out of 4.16 and 4.17. Users have not provided any description of their actions when the crash occurred. The top line of the callstack and the source context ...

FKeyHandle internal static atomic counter can overflow on long running games depending on usage pattern

UE - Runtime - Animation - Sep 24, 2025

Structure FKeyHandle stores an internal index, which is initialized from a static atomic counter in the default constructor: +----- FKeyHandle::FKeyHandle() { | static std::atomic<uint32> LastKey ...

ENGINE: CRASH: One off Editor Crash with ANavLinkProxy::GetComponentsBoundingBox() navlinkproxy.cpp:189

UE - AI - Oct 20, 2016

One off editor crash. [Link Removed] Error Message Access violation - code c0000005 (first/second chance not available) Call Stack of Most Recent Crash ANavLinkProxy::GetComponentsBoundingBox() na ...

PlayMontages can break after binding an actor with an AnimInstance inside a LevelSeuqence.

zComponent - Archive - May 28, 2025

When an Animation Sequence is overridden by a LevelSequence, and later reverts to its original animation state, the AnimInstance fails to properly reinitialize. This prevents subsequent animation lo ...

Once an actor channel is closed by NetCullDistance, root motion movement synchronization stops working

UE - Framework - Networking - Jul 12, 2021

Properties that uses DOREPLIFETIME_ACTIVE_OVERRIDE (ex. RepRootMotion ) will also skip replication when an actor channel is newly opened. This means that if the variables on the server side do not c ...