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

UE - World Creation - Worldbuilding Tools - 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 - Graphics 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 ...

[CrashReport] UE4Editor_Engine!CropRawTrack() [animsequence.cpp:1798]

OLD - Anim - Dec 14, 2018

Comment from user in crash groupTried to delete frames in an animation ...

AutoCreateRefTerm does not provide a way to specify that a TArray property within a struct should have a default value created for it if none is provided

UE - Gameplay - Feb 9, 2018

The current implementation of AutoCreateRefTerm does not allow for a default value to be automatically created for a TArray contained within a struct that is passed into a function as a parameter. I ...

Copied references to Texture2D assets are not formatted correctly when the .csv containing those references is made into a Data Table asset in the Engine.

Tools - Feb 26, 2015

Importing a .csv file that contains references to assets in the project requires the user to copy the references for each asset again before they will work correctly. The references do not need to b ...

Crash when trying to launch ShooterGame with -game

UE - Online - Jul 11, 2017

Might be related to the changes in //UE4/Release-4.17 at CL 3527005. I was also able to repro this via PIE-Standalone Game in the editor. When I repro'd this with PIE-Standalone Game the Standalone ...

Editing and committing changes to a PackedLevelActor Blueprint results in a crash

UE - World Creation - Worldbuilding Tools - Level Instances - Apr 5, 2022

Repro Ratio: 3/3 Regression was tested in //UE5/Release-5.0-EarlyAccess CL-16682836 since this is a new feature of UE5.  The issue did happen ...