Get Mouse Position Blueprint node returns different values outside of viewport depending on whether it was called from Event Tick, or within an Actor function

UE - Gameplay - Nov 15, 2018

There seems to be a discrepancy between the output of Get Mouse Position node depending on whether the node is inside an Actor function or called from Event Tick. If the node is present inside a fun ...

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

UE - Anim - Sequencer - MRQ - 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 ...

Race condition in full builds of UE4 engine source

UE - Foundation - Cpp Tools - UnrealBuildTool - Sep 26, 2019

This is a race condition caused by how "Clean.bat", a batch file used during rebuilds, tries to manually rebuild the UnrealBuildTool project when it runs. This causes a spam of UnrealBuildTool build ...

Culling Distances Not Working For Static Mesh in Procedural Content Generation Tool and Foliage Tool

UE - World Creation - Procedural Tools - Mar 28, 2025

When creating Foliage or Procedurally Generated Content the culling settings of the Static Meshes do not apply correctly. As soon as either a minimum or maximum cull distance is set the Static Meshe ...

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 sometimes crashes when trying to compile an Animation Blueprint that extends a class with AnimInstanceProxy

UE - Anim - Runtime - Anim Blueprints - Jan 10, 2023

Reproduced 3/3 times, issue does not occur in //UE5/Release-5.0 - CL 20979098 Binary. Confirmed Regression. Seems to work fine when compiled once, but after the 2nd or 3rd time it crashes. ...

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 ...