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 ...

Hot Reload does not update blueprint pins

UE - Gameplay - Blueprint - Jan 15, 2015

When changing the variable type or return type of a function in code and hot reload in the editor, blueprints that use the variable/function do not have their pins updated until the editor is closed ...

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. ...

[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 ...

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 ...

Regression - Nested scene component subobjects are no longer being registered when the owning scene component is added to an existing Actor instance as an instanced component.

UE - Gameplay - Components - Nov 16, 2016

This is a regression that was introduced with changes made to address issues with native vs. non-native component registration at Blueprint construction time ([Link Removed]). Prior to those change ...

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 ...