Niagara color picker user parameter preview no longer updates until confirmation

UE - Niagara - Apr 18, 2025

Starting with UE 5.4, the Color Picker Tool no longer updates preview values in real time for certain editor windows like Niagara when working with User Parameters. This behavior is a regression fr ...

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 ...

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 ...

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 ...

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 ...

Crash when building lighting while in PIE

UE - Graphics Features - Feb 21, 2017

NOTE: This issue is similar to (same callstack) as [Link Removed], however this issue is still occurring in 4.15.0. Error Message: Access violation - code c0000005 (first/second chance not availab ...

Using a Macro to access a variable from another Actor causes a crash in Standalone

UE - Gameplay - Blueprint - Jun 8, 2015

Using a Macro to access a variable from another Actor causes a crash in Standalone. This does not seem to affect any other preview in editor, nor packaged games. Reproduced in 4.7.6, 4.8 Preview 4, ...