Niagara Scalability Crash When Processing Significance

UE - Niagara - Jun 4, 2025

Method FNiagaraScalabilityManager::ProcessSignificance() iterates on indices from Context.SignificanceIndices and uses them to access the State and ManagedComponents arrays. It can then decide to cr ...

Editor crashes when changing skeletal mesh if another skeletal mesh component is attached when using master pose node

OLD - Anim - Jan 27, 2020

The crash only occurs if the additional skeletal mesh component is used with Set Master Pose Component (see ToggleAttach function in the TopDownCharacter BP). It doesn't seem to matter what mesh we' ...

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. ...

GeometryCollectionPhysicsProxy::FieldParameterUpdateCallback() not removing invalid Commands, leading to performance issues

UE - Simulation - Visual - Aug 30, 2025

GeometryCollectionPhysicsProxy::FieldParameterUpdateCallback() not removing invalid Commands, leading to performance issues. The licensee has provided their analysis: We seem to have stumbled acro ...

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 ...

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 ...

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] Cook error: UATHelper: Cooking (Windows): LogSavePackage: Warning: UATHelper: Cooking (Windows): Referencers of MovieSceneTimeWarpSection /Game/ChildSequence.ChildSequence: ...

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 ...

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 ...