Non-existing config file loading could cause memory leak

UE - CoreTech - 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 ...

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 ...

[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 ...

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.

UE - Anim - Sequencer - 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 - 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 ...

Crash in AWorldDataLayers::InitializeDataLayerRuntimeStates() when quickly unloading then loading a sub-world partition

UE - World Creation - Worldbuilding Tools - Data Layers - Mar 6, 2025

From licensee: Since we integrated 5.5, we are experiencing a crash in AWorldDataLayers::InitializeDataLayerRuntimeStates() on this line check(ActiveDataLayerNames.IsEmpty() && LoadedDataLayerN ...

Crash on iOS9 when using Apple's CFNetwork library

UE - Platform - Mobile - Dec 6, 2016

Many clients have hit a crash due to an Apple library using operator delete on a memory block that was not allocated with operator new. This happens with the following callstack on iOS9 in UE4.13 o ...

Loading a blueprint with an invalid gameplay tag container pin causes ensure and data loss

UE - Gameplay - Feb 23, 2021

The gameplay tag system depends on tags being registered with the global manager as valid in order to correctly read them off disk. Two different issues are combining to cause a confusing ensure and ...