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 ...

Material Function Instances do not show up in the Material Function Call node

UE - Rendering - Architecture - Materials - Jun 5, 2023

This is not a regression. Tested in //UE5/Release-5.1 CL23901901. The Material Function Instance can be dragged and dropped into the Material Function Call. ...

HDR (eye adaptation) visualization has incorrect output when Allow static lighting is disabled

UE - Rendering - Features - Mar 19, 2025

Licensees have reported that this issue occurs in UE 5.5 and does not appear to occur in UE 5.4 or with Substrate enabled. ...

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 ...

Niagara - When a Static Switch is used inside a Niagara Function Script with "expose as pin" disabled, its Selector variable is exposed as an input on function call nodes. However, this input incorrectly loses its "static" type.

UE - Rendering - Architecture - Niagara - Apr 7, 2025

Consider a Niagara Function Script containing a Static Switch node with the "Expose as Pin" option disabled for its selector variable. When the function is called by another Niagara Function or Niag ...

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 ...