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 ...

iOS movie (mp4) has no sound in the playback.

UE - Platform - Mobile - May 16, 2017

There is no sound in the movie play in iOS, built with 4.16 GitHub source code version. you can simply reproduce using attached sample project. This is reproduced in iPhone 5s(10.3.1) iPhone 6(iOS ...

Crash during Datasmith file import when not using Keep Hierarchy

TM - Interoperability - Jun 24, 2025

Reported to support. The user has reported that one of their .udatasmith files will consistently crash in TM 2025.1.1 during import. This was consistently reproducible when importing using Collaps ...

Animated characters may appear in A pose after loading a file with Path Tracer enabled

TM - Rendering - Mar 12, 2025

When saving a file with Path Tracer enabled at the time of save, animated characters will appear in an A pose state. This will persist until Path Tracer is disabled. Occurs in Twinmotion 2024.1.2 a ...

A warning is needed for turning off "Update Navigation Automatically", large nav meshes can cause crashes

UE - AI - Jul 7, 2015

A warning is needed before allowing users to uncheck update Navigation Automatically. A user has done so and then created a nav mesh that was 1,000,000 by 1,000,000 in size and they can no longer op ...

Bug in ULevel::FixupActorFolders.

There is a potential bug in ULevel::FixupActorFolders() in the FixDuplicateFolders section: Suppose you have a folder hierarchy that looks like this:A B(1)B(2) C(1)B(3) C(2) where the letters ...

[CrashReport] UE4Editor_CoreUObject!UObjectBase::IsValidLowLevelFast() [uobjectbase.cpp:294]

UE - Foundation - Core - Aug 22, 2017

This is a common crash in the 4.16 and 4.17 releases. User DescriptionsWriting a custom component in C++. Hotcompiled it through VS2017. Had the BP editor open with a class derived from that compo ...

Shader Complexity viewmode does not work on masked materials

UE - Graphics Features - Oct 16, 2019

In engine versions 4.23 and above, the Shader Complexity Viewmode doesn't render appropriately for meshes with masked materials. Tested in 4.22.3 (CL - 7043647), 4.23 (CL - 8386587), 4.24 (CL - 961 ...

Importing fbx with armature resulting in crash

UE - Editor - Content Pipeline - Import and Export - Jan 20, 2020

Importing an fbx file with armature on MAC results in crash Tested: 4.23.1 CL#9631420, 4.25 CL#10889200 ...

Media Textures assigned at run time are not being applied to the assigned mesh

Media Framework - Feb 21, 2020

Dynamically created media texture is not applied to assigned meshes.  Tested in:  4.23.1 CL#9631420, 4.25 CL#11574810 ...