Set user focus for player 0 will cause other local players to lose input

UE - Gameplay - Input - Feb 28, 2019

When the player at index 0 sets its user focus it will cause other players to lose input. This does not occur when setting the user focus of players with an index higher than 0. ...

World Source in Take Recorder does not record auto-tracked actors properly

UE - Virtual Production - Tools - Take Recorder - May 23, 2025

The Take Recorder plugin allows for multiple sources to be recorded during gameplay. The World Source is expected to record everything in the level when the Autotrack Actors option is enabled. Once ...

Crash after adding Virtual Bone, then Creating Asset

OLD - Anim - Jul 5, 2017

Occurs on? 4.16 - 3466753 - YES 4.17 - 3521650 - YES Error message: Assertion failed: RefBonePose.Num() == NumBones [Link Removed] [Line: 4400] Source Context:4387 ResetAnimation(); 4388 ...

Exception generated launching Horde Agent built with 5.6

UE - Foundation - Horde - Server - Jul 28, 2025

The source of the problem seems to be using IOptionsSnapshot with a Singleton. Per the MS documentation for IOptionsSnapshot, "Is registered as Scoped and therefore can't be injected into a Singleto ...

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 ...

PATH not passed to NMake script when building Android from Visual Studio

UE - Foundation - Cpp Tools - UnrealBuildTool - Jan 25, 2023

After upgrading from UE5.0.3 to UE5.1, we started seeing this error when trying to build Android Development from Visual Studio (VS2022 17.2.1): Running UnrealBuildTool: dotnet "..\..\Engine\Binari ...

Crash when upgrading Nvidia GFX driver from Version 457.85 with open Project

UE - Graphics Features - Nov 18, 2022

Repro Rate: 5/5 Summary: When opening a Project in UE version 5.1.0 with Nvidia GFX driver version ###, the user is notified that there are known issues with this driver through a pop-up:WARNING: K ...

Illegal reference to private object when cooking a child level sequence with a time warp track

UE - Anim - Sequencer - Apr 28, 2025

Slack: [Link Removed] Another Slack: [Link Removed] Cook error:UATHelper: Cooking (Windows): LogSavePackage: Warning: UATHelper: Cooking (Windows): Referencers of MovieSceneTimeWarpSection /Gam ...

Crash on attempt to clear(NullifyInstance) of duplicated Hierachial Instanced Static Mesh

Tools - May 31, 2019

When creating an C++ Actor with a Hierarchical Instanced Static mesh. when duplicating such an actor with mesh instances, the instances are not visible on the level. In this state, calling HISM comp ...

Crash when launching Google VR project

UE - Platform - XR - Dec 12, 2016

Attempting to launch a packaged Google VR game on android causes the game to crash. This has occurred on two other devices. This occurs in Main as well as Dev-VR. ...