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' ...

Linux Twin Stick Shooter sound does not have constant tempo

UE - Platform - Linux - Oct 9, 2015

The firing sound in the Twin Stick Shooter template on the Linux machine does not have a constant tempo. The firing sound changes between evenly spaced sounds and closely spaced sounds. I do not se ...

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. ...

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 ...

Automatic Animation Compression Results in Crash

OLD - Anim - Dec 1, 2015

Using the "Automatic" option to compress animation results in crash 100% in UE4.10 but does not occur in UE4.9.2. *Regression ...

SVN SASL binaries may be causing crashes for some users

Tools - Feb 21, 2017

Some users are reporting crashes when attempting to connect to SVN after upgrading to 4.15. The only relevant change to SVN was the update of the 1.9 binaries to support SASL, so it's possible that ...

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 ...

It is possible to get large Aspect Ratio values when using an Ultra-wide monitor on Linux

UE - Platform - Linux - Jul 22, 2019

Attempting to use the Editor with a 32:9 Ultrawide monitor (5120x1440) causes the ratio sizes to be multiplied by 868.000000. ...

Widgets With Retainer Boxes Are Selected When Behind Widgets Without One

UE - Editor - UI Systems - Dec 24, 2019

When a widget that has a retainer box is behind another widget that doesn't have one it will call it's onclick instead of the one in front of it in the UMG when clicked (see attached gif). This beh ...