Phaser module is malfunctioning

UE - Audio - Apr 9, 2019

The phaser module that is part of the new Audio Engine causes audio from a Sound Cue to mute after playing for one second. The user states that the issue comes from the Phaser.cpp file producing a N ...

Python crash the engine at exit.

UE - Editor - Workflow Systems - Oct 25, 2022

A UDN reported various crashes at exit in the embedded Python library. I was able to repro the issue in Release-5.1 and trace it back at the point where python runs its garbage collection in Py_Fina ...

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 ...

Physics Substepping doesn't have the same effect from 4.15 to 4.16

OLD - Anim - Aug 8, 2017

Physics Substepping doesn't have the same effect from 4.15 to 4.16. In 4.16+ the ponytail in the provided project will have a jitter effect even with substepping enabled. This is a regression: Work ...

[CrashReport] UE4Editor_UMG!TBaseDelegate<FMargin>::operator=() [delegatesignatureimpl.inl:381]

UE - Editor - UI Systems - Aug 29, 2017

This is a longstanding and common UMG crash that has affected more than 200 users since at least the 4.15 release. User DescriptionsI was working in the UI and undid several last changes in quick s ...

[CrashReport] UE4Editor_UnrealEd!FBlueprintCompileReinstancer::ReplaceInstancesOfClass_Inner() [kismetreinstanceutilities.cpp:1880]

UE - Gameplay - Blueprint Compiler - Oct 5, 2017

This is a somewhat common crash that has occurred throughout the 4.17 release. Users have not provided any description of their actions when the crash occurred. The callstack is similar to some ol ...

[CrashReport] UE4Editor_WorldBrowser!FMulticastDelegateBase<FWeakObjectPtr>::RemoveAll() [multicastdelegatebase.h:81]

UE - World Creation - Worldbuilding Tools - World Composition - Nov 2, 2017

This is a trending crash coming out of 4.18 and may be a regression. Users have not provided any descriptions of their actions when the crash occurred. Source Context 72 /** 73 ...

Always Relevant actor may replicate incorrect movement mode when the walkable floor becomes irrelevant

UE - Gameplay - Player Movement - Feb 26, 2024

When the character class is set to always relevant, if a client travels very far away from another character, such that the character is relevant but the component they're standing on is not (but al ...

PakFiles: Unmounting PakFile while requests are still in progress causes assertion failure in UnMount

UE - Foundation - Mar 31, 2022

[Link Removed] Licensee is using the chunk downloader. On Shutdown method of their GameInstance, they call FChunkDownloader->Finalize. When they quit the game (Alt+F4) during a chunck download an a ...

[CrashReport] TOctree<TVolumeLightingSample<3>,FLightVolumeOctreeSemantics>::TConstElementBoxIterator<TInlineAllocator<99,FDefaultAllocator> >

UE - Graphics Features - Oct 5, 2017

This Jira is a continuation of [Link Removed]. This is the same callstack which users are submitting, however the other Jira eventually got specific repro steps which were verified fixed in 4.17.0. ...