USD Stage is not available on Mac and Linux

UE - Editor - Content Pipeline - Import and Export - Dec 17, 2019

On Mac and Linux the option to open the USD Stage window is not there like it is on Windows. This is not a regression since USD Stage was not preset in 4.23.1 (CL-9631420) on any platform. ...

Attached actor in Sequencer does not detach regardless of the detach state settings until Sequencer is restarted

UE - Anim - Sequencer - Jan 29, 2020

Attached objects in sequencer do not detach with newly specified "When Finished" property until Sequencer is restarted.  Tested in: 4.23.1 CL#9631420  4.25 CL#11062379 ...

NaN is handled differently when clamped on Windows and Android/iOS

UE - Platform - Mobile - Oct 18, 2017

NaN (Not a Number) is handled different when clamped on Windows and Android/iOS. If you clamp a NaN (Acheived by -3 ^ 0.2 in the reproduction project) from 0.0 to 1.0 and then print the result, you' ...

Scale with Width on Landscape Splines offsets plane mesh on Z axis

UE - LD & Modeling - Terrain - Landscape - Apr 22, 2015

If "Scale with Width" is set on a landscape spline with a plane mesh, the plane will offset on the Z axis. In most other cases, scaling along the z axis does not affect planes. ...

Packaged Game Ensure Crash when GameInstance working with Async loading thread

UE - Foundation - Core - Jul 23, 2019

In Engine 4.23 Preview, when AsyncLoadingThread is enabled and GameInstance is loaded from a Blueprint, the Engine will crash. ...

When Adding Custom Bindings, get ensure that "Multiple persistent shared references detected for Sequencer..."

UE - Anim - Sequencer - Nov 17, 2025

Ensure: Error    LogOutputDevice      Ensure condition failed: SequencerRefCount == 1 [Link Removed] [Line: 967]  1. Error    LogOutputDevice      Multiple persistent shared references detected f ...

Artifacts in imported GLB and GLTF files

TM - Interoperability - Mar 10, 2025

Reported in SF [Link Removed] Client reports that many of their GLB and GLTF files they use appear with visual artifacts when imported to Twinmotion. These artifacts only appear in Twinmotion and n ...

Inconsistent events triggered by FlushProcessedKeys during keyboard hold input

UE - Gameplay - Input - Dec 20, 2024

Key repeats from the OS do not affect the EnhancedInput normally, but it causes inconsistent event triggers when FlushProcessedKeys is called with holding a keyboard key down. Removing references t ...

Reset seed on emitter looping not working properly

UE - Niagara - Dec 31, 2019

The "Reset Seed on Emitter Looping" has no effect when enabled.   Tested in: 4.22.3 CL#7053642 , 4.23.1 CL#9631420 , 4.25 CL#10868506 ...

Lighting build fail due to failing to open channel for material data

UE - Graphics Features - Apr 21, 2017

Licensee reports lighting build fails for their specific levels which were created in 4.14.1 then moved to 4.15.1. Workaround: Setting LogLightmassSolver verbose level to Warning can show "Warning ...