Crash on iOS9 when using Apple's CFNetwork library

UE - Platform - Mobile - Dec 6, 2016

Many clients have hit a crash due to an Apple library using operator delete on a memory block that was not allocated with operator new. This happens with the following callstack on iOS9 in UE4.13 o ...

If using SetAlignmentInViewport in Construct, the value with it is ignored

UE - Editor - UI Systems - UMG - Jan 27, 2023

If SetAlignmentInViewport is called in the UMG Construct, it is ignored internally. This is due to a change that came in 5.1, so it worked fine in 5.0. First, when the Set Alignment in Viewport nod ...

iOS Metal-based build crashes at launch with sub-levels.

Tools - May 16, 2016

Application crashes when deploying a game to iOS with Metal enabled. This has only been reproduced if a sub-level has been added to the starting level within the project. This seems to only happen ...

Bloated instruction counts in the material editor causing long compiles

UE - Graphics Features - Apr 17, 2019

artists are dealing with greatly increased iteration times due to long shader compiles when working in the material editor. This has regressed over time as we add more features to the point were wor ...

wire import crash on file generated by alias 2021.3

UE - Editor - Content Pipeline - Import and Export - Jul 20, 2021

Our company has updated Alias to 2021.3.1 and now Datasmith crashed when importing .wire files. Previously we had Alias 2019 and Alias 2021.1 installed. Now just Alias 2021.3.1 and then the issue be ...

Import then cancel while file is read leads to potential crash

TM - Interoperability - Oct 6, 2025

1/ Import a file with mootools such as an fbx 2/ while the file is still read, cancel the import Result : may crash few times after (when theoretically the file has finished being read) - not repr ...

[AI] StateTreePropertyRef does not have option for Promote to Parameter

UE - AI - StateTree - Nov 5, 2025

I got a report from one of my designers that since we took 5.6, they have been unable to see the "Promote to Parameter" options when attempting to bind an output from one of our common tasks. I took ...

Distant paint/scatter grass not rendered in PT exports

TM - Rendering - May 5, 2025

Reported in SF [Link Removed] In TM 2025.1.1, in PT renders with large amounts of scattered or painted vegetation, distant grass may not appear in exported renders that would previously appear in t ...

[CrashReport] Linux crash - TOpenGLBuffer<FOpenGLBaseVertexBuffer, 34962u, &()

UE - Platform - Linux - Sep 14, 2017

This is an infrequent Linux crash that has affected a few users in 4.17.1 Callstack from Log[2017.09.12-17.23.41:651][ 0]LogRHI: OpenGL MajorVersion = 4, MinorVersion = 5, ShaderPlatform = GLSL_43 ...

Farfield shadow in lumen scene

UE - Graphics Features - Jul 21, 2025

Shadows in the Lumen Scene from Lumen's Direct Lighting do not match the world when in the Lumen Far Field. This leads to shadows where there should not be any, and missing shadows where there shou ...