Crash on Unreal Editor Exit due to subclass of UEditorUtilitySubsystem

UE - AI Workflows - UI Systems - UMG - Jun 18, 2024

Since UE5.4, it has been reported that if there's a class derived from UEditorUtilitySubsystem, the program crashes when the editor exits. This is because the code added in CL30853505 accesses freed ...

VRS Cvar Crash during CollectPSOInitializers when CVarEnableVRS.GetValueOnRenderThread() causes Ensure failure

UE - Rendering - RHI - Aug 21, 2026

We are running into an ensure that is triggered when CVarEnableVRS.GetValueOnRenderThread() is called on the game thread from FVariableRateShadingImageManager::IsAttachmentVRSEnabled. This happens ...

FStateTreeRunParallelStateTreeTask and TStateTreePropertyRef

UE - AI - StateTree - Dec 2, 2025

When using a state tree that has a StateTreePropertyRef as a parameter in parallel any references will fail to resolve using the GetPropertyRef node. ...

BP - Nativized build will crash at runtime if a non-nativized child that inherits from a nativized parent containing a ChildActorComponent sets the CAC class to a non-nativized child of a nativized BP class.

UE - Gameplay - Blueprint - Jan 26, 2020

Current workaround: Add a dummy variable to either BP_Owner_Child or BP_CAC_Child to force one of the two to be nativized. ...

[MRQ] Deleting all jobs after rendering queue with executor causes an assertion to fail.

zComponent - Archive - Apr 18, 2022

Deleting all jobs after rendering queue with executor causes an assertion to fail. Repro Rate: 3/3 Tested this in //UE4/Release-4.27 @ CL#18319896 by utilizing a For Each Loop and Delete Job node ...

In editor, sub level instance's streaming state persists incorrectly after toggling Level Behavior without saving

UE - Engine Scaling - Streaming - Level Instances - Jun 11, 2025

When adding a sub level with world partition streaming to a main level where the streaming is also enabled, setting* Level Behavior* of the sub level to Standalone, and saving the result, in the fir ...

iOS Shipping Build using std::thread crashes on launch

UE - Platform - Mobile - Jun 2, 2017

A user is reporting that using the following code in a GameMode class causes shipping iOS packages to crash on launch:void ANOGSSDKGameModeBase::StartPlay() { std::thread([](){ std::clog << "THRE ...

Editor Crashes when spawning a Physics enabled object inside another

UE - Simulation - Physics - Sep 22, 2017

Editor Crashes when spawning a Physics enabled object inside another. Regression: Unknown Can Test in Main if requested. ...

Console command “showflag.rendering 0” causes crash

UE - Rendering - Architecture - Jul 10, 2025

A crash occurs when the console command “showflag.rendering 0” is executed. This does not occur in UE5.5, so it is a iassue in UE5.6. ...

[MRQ] Simulating in editor during runtime rendering causes an assertion to fail after rendering is done

UE - Rendering - Features - Apr 19, 2022

Simulating in editor during runtime rendering causes an assertion to fail after rendering is done. Repro Rate: 4/4 Tested this in //UE4/Release-4.27 @ CL#18319896 and the issue did not occur there ...