HTML5 fails to compile on Mac/Windows - Shipping

UE - Platform - Apple - Jan 13, 2017

HTML5 fails to compile on Mac when built for shipping in binary I did not see this when packaging for development yesterday Does not occur in 4.14.3 The error appears to be WebGL relatedError: Web ...

[CrashReport] Mac crash - UE4Editor-Slate.dylib!PrepassWindowAndChildren(TSharedRef<SWindow, (ESPMode)0>)

UE - Platform - Apple - Oct 27, 2017

This Mac crash originally occurred in 4.15 around March 2017, then decreased in frequency during 4.16 and 4.17. It may be starting to trend again in 4.18. There is one record of this occurring in 4 ...

WP HLOD Crash on Small Cell Sizes

UE - World Creation - Worldbuilding Tools - HLOD - Jan 8, 2024

tvOS/IOS: Fails to Build with dSYM Options Enabled Due to DsymExporter Erroring Out

UE - Platform - Mobile - Jan 22, 2019

When attempting to package for tvOS or iOS with the generate dSYM options enabled, numerous instances of the following errors occur:[2019.01.21-20.53.35:739][138]UATHelper: Packaging (tvOS): [2019 ...

Garbage Collection Causing Noticeable Hitches

UE - Foundation - Core - Apr 11, 2016

Garbage Collection is causing noticeable hitches on whatever interval it is run on. This is noticeable in the UE4 Profiler, as you will see a spike every X amount of seconds, depending on how often ...

Regression: FAnimInstanceProxy memory leak when BeginDestroy() called on UAnimInstance before USkeletalMeshComponent

UE - Runtime - Animation - Feb 10, 2025

In UE 5.5, the fix applied by CL 36529858 in ue5-main updated USkeletalMeshComponent::ClearAnimScriptInstance() to call AnimScriptInstance::UninitializeAnimation() on the animation instance. This, i ...

Adding Angular Impulse on Begin Play causes a Crash

UE - Simulation - Physics - Jun 29, 2016

Calling Add Angular Impulse on BeginPlay causes the editor to crash. Workaround: Adding a short (.01s) delay after BeginPlay prevents the crash. Regression: No, crash occurs in 4.11.2 as well. ...

In the level editor, when configuring a component that is part of an actor blueprint, adding entries to a TMap with C++ enum keys results in duplicate keys and an incorrect warning popup.

UE - Editor - Jan 22, 2026

Note: This started happening in UE 5.4 and persists up to latest. It is probably related to [Link Removed] Closed ([Link Re ...

Packaged Win32 Shootergame crashes in OpenGL

UE - Graphics Features - Nov 4, 2014

Packaged Win32 Shootergame crashes in OpenGL. This cropped up while testing on Windows XP, but occurs on all platforms if you launch in OpenGL. QA REGRESSION: YES WORKING: Regressing now BROKEN: ...

Lighting Build fails with World Settings Error

UE - Graphics Features - Jan 16, 2015

Lighting Builds seemingly successfully but produces a Map Check Error for World Settings. There are several things that can be done to "eliminate the issue" and I have separated them into different ...