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 ...

Custom Depth range is different than Pixel Depth range

UE - Graphics Features - Sep 25, 2025

Shaders that compare custom depth and pixel depth get wrong output values because the ranges are different. This error is most noticeable over large distances. The difference in ranges is due to t ...

When r.SSR.Stencil is enabled, there is wrong logic observed.

UE - Graphics Features - Dec 19, 2025

When r.SSR.Stencil is enabled, the areas with high roughnesss are not discarded and Unlit materials are incorrectly handled. See the linked EPS case (Additional Info URL) for a full explanation of ...

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 ...

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 ...

Capsule component Shape values can be glitched inside of Actor class bp

UE - Gameplay - Components - Oct 29, 2015

Capsule component Shape values can be glitched inside of Actor class bp This effects 4.9.2 and 4.10 Preview 3, however it is working properly in 4.11-2736016 User Description: Alright, so the Cap ...

[CrashReport] Assertion failed: GetOuter()==NULL in UE4Editor_Core!FText::IsEmpty

Tools - Apr 17, 2017

This is a top 10 crash affecting many users. It is believed it may be related to the auto listen / reimport feature. The callstack shares similarities to past tickets, such as:[Link Removed][Link R ...