StaticMesh export to FBX crashes if UVElements has more channels than VertexInstanceUVs

UE - Editor - Content Pipeline - FBX - Jan 22, 2026

As indicated in the repro steps, we have a StaticMesh asset that, for some reason, has a mismatch in their serialized bulk data where:MeshDescription->GetNumUVElementChannels() == 2FStaticMeshConstA ...

Enabling Use Pawn Control Rotation on a SpringArm component does not set the rotation values to zero, and subsequent rotation is not allowed after the setting is disabled

UE - Gameplay - Player Movement - Jan 2, 2016

Enabling Use Pawn Control Rotation on a SpringArm component does not set the rotation values to zero. Subsequently disabling Pawn Use Control Rotation make rotation of the component impossible until ...

Editor crashes when calling "Begin Draw Canvas to Render Target" on Event Tick

UE - Graphics Features - Aug 20, 2020

The recent hotfix caused this workflow to begin crashing. User reports that it worked as intended in 4.25.2 (CL-13908680). We are unable to reproduce it in 4.24.3 (CL-11590370) either. Crash is ha ...

Blueprint child asset is set moved to offset position when set to simulate physics

UE - Gameplay - Mar 3, 2015

When setting up a BP via the scene with the new method of adding components and converting to a BP the child component that is set to simulate physics enabled will be offset from its original positi ...

Cyrillic user name with Windows will prevent APEX cloth apb files from importing

OLD - Anim - Jan 29, 2015

When the user name on Windows is set to cyrillic importing APEX cloth assets will fail. I'm not sure what other systems this may also affect, but adding a cloth apb asset to a skeletal mesh will cau ...

Dithered LOD Transition does not work on some mobile devices

UE - Platform - Mobile - Aug 27, 2019

I tested with some mobile devices and Dithered LOD Transition did not work on Huawei P20 Pro. This problem does not occur with Snapdragon. This problem does not occur with Snapdragon like Pixel 3. ...

Group movement distorts with scenes of different scale in actor blueprint

Tools - Dec 5, 2017

There is an issue with selecting multiple meshes that are children of different scenes when the scale is different than the default. moving the static meshes together causes them to move at differen ...

Null Redirector For Main Game Level Is Packaged Without Error After Fixing Redirector

Tools - Feb 24, 2020

After moving a level into a folder and fixing the redirectors (right click in content browser) the project will package a Null reference without throwing an error. This will let you create a project ...

NaN Present on IOS after UE5.6 Because of Removal of MobileSpecularGGX

UE - Platform - Mobile - Sep 24, 2025

In UE5.6 MobileSpecularGGX was removed and now mobile devices also run D_GGX. The problem is that there are still cases where very bright values are produced (image 1) and thus NaNs appear in the Bl ...

When switching versions of UE4 the folder colors do not migrate with the project

Tools - Feb 27, 2015

User reports when creating a project and changing the folder colors in 4.6, then opening the project in 4.7/4.7.1, the folders go back to their default color. Users have also reported this happenin ...