Apex Destruction - Destructible Mesh disappears after Fracture

UE - Simulation - Physics - Destruction - Jan 3, 2020

Fracturing a mesh with Apex Destruction in 4.24.1 (CL-10757647) causes the mesh to disappear after clicking Fracture. This behavior was not present in 4.23.1 (CL-9631420). Unable to confirm this in ...

Crash when generating mip maps for texture

UE - Graphics Features - Dec 23, 2019

Generating mip maps results in crash and seems to duplicated 1x1 mip level. NOTE: The bug was originally reported in 4.23.1, however, for some reason I was able to open the texture in 4.23.1 afte ...

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. ...

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 ...

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 ...

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 ...

Occlusion Culling incorrectly culling objects

UE - Graphics Features - Aug 26, 2020

When playing in PIE/camera moving from left to right, pieces of the floor grid are culled out when they are not supposed to be. I was able to replicate this issue, however after I brought up the c ...

Crash when using +CVars=r.MobileContentScaleFactor=2

UE - Platform - Mobile - Jan 11, 2016

Iphone 6 Plus crashes when using +CVars=r.MobileContentScaleFactor=2, but it will run if you use +CVars=r.MobileContentScaleFactor=1. The project linked is set up with +CVars=r.MobileContentScaleFac ...