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 ...

Paper2D performance regression due to TArray resizing

UE - Graphics Features - Aug 16, 2019

We've noticed after upgrading our heavy Paper2D project to 4.22 that tilemap performance has been massively degraded compared to previous versions. After some digging we found out that it's due to a ...

Behavior Tree (BT) services added to root nodes call the initial tick twice

UE - AI - Nov 20, 2024

Behavior Tree (BT) services added to root nodes call the initial tick twice A BT Service with the setting "Call Tick on Search Start" enabled will execute the initial tick twice when added to the ro ...

Crash when returning to viewport from immersive mode with an editor window tabbed beneath

Tools - Mar 2, 2015

When the user enters immersive mode by hitting f11 and then opens the material editor, (which opens tabbed in the editor underneath the immersive display)The engine crashes when hitting attempting t ...

BuildPatchTool crashes on Mac and Linux when building android or ios with multiple chunks

Portal - Feb 18, 2020

"It seems that deallocation of TLazySingleton<FInternationalization> causes unhandled exception. If DISABLE_LAZY_SINGLETON_DESTRUCTION=1 is provided - the build completes successfully" ...

Editor crashes due to a material that contains MPCs migrated from another project

UE - Rendering - Architecture - Materials - Apr 29, 2024

[2024.04.29-16.49.46:563][970]LogUObjectGlobals: Warning: LoadPackage can't find package /BEURRE_040824_041224/NewMaterialParameterCollection. [2024.04.29-16.49.46:563][970]LogUObjectGlobals: Warning ...

Search field in 'Quickly Add to Project' fails with Chinese Pinyin input unless manually focused

UE - Editor - UI Systems - Localization - May 28, 2025

A licensee reported that under the Chinese language setting in UE5, using the “Quickly Add to Project” button results in incorrect or ignored input when entering text via Pinyin IME. If the user sta ...

Fracture Mode > "Remove-On-Break" setting: Cluster Crumbling causes flickering

UE - Simulation - Physics - Destruction - May 10, 2025

Fracture Mode > "Remove-On-Break" setting: Cluster Crumbling causes flickering. Once the Remove-On-Break Cluster Crumbling effect is activated, there is a small delay between the disappearance of th ...

[MetaSounds][Sine Generator] - Ensure in MetasoundEnum.h

UE - Audio - MetaSounds - Mar 25, 2022

Live Ensure seen in Crash Reporter. Crash Reporter Link: [Link Removed] Hit 13 times by 4 users.Ensure condition failed: Converted [File:D:\build\++UE5\Sync\Engine\Plugins\Runtime\Metasound\Source\ ...

Crash when changing a Play Node's "Sequence" to a Montage

OLD - Anim - Jan 20, 2016

I understand that this is not something you're intended to be able to do (Montages aren't used this way), but we should bar the user from inserting a montage into this variable slot. Crash occurs w ...