Different Number of Frames imported from the same FBX between UE 4.8 and 4.9

OLD - Anim - Sep 14, 2015

Using the same import settings in UE4.8 and UE4.9 will result in a different number of frames of an animation being imported from the same FBX file. If you import the same fbx animation which in M ...

Instanced object in an array property of an actor component is invalidated and marked for garbage collection on undo

UE - Gameplay - Jun 4, 2024

If an actor component contains a TArray of instanced objects, some of those object instances can get incorrectly invalidated and marked for garbage collection in certain situations, possibly resulti ...

Assigning APX Cloth asset to material element

UE - Simulation - Physics - Character - Jun 17, 2016

When assigning an imported apx file to the clothing drop down under the material element of this imported Skeletal Mesh will result in a crash. Tested in: 4.11.2 CL-2946394 4.12.3 CL-3013449 Dev ...

Import then cancel while file is read leads to potential crash

TM - Interoperability - Oct 6, 2025

1/ Import a file with mootools such as an fbx 2/ while the file is still read, cancel the import Result : may crash few times after (when theoretically the file has finished being read) - not repr ...

Setting a value Material Parameter Collection to Material will cause crash

UE - Graphics Features - May 2, 2016

Adding a Material Parameter collection to a material, setting its value, then saving the material will cause a crash. This was only able to be reproduced on Mac and did not affect the Windows versio ...

Pasted material function nodes lose their connections

UE - Rendering - Architecture - Materials - Dec 3, 2019

The fix for [Link Removed] caused a regression where links to material nodes no longer carry over when a group of nodes is copied and pasted ~ User submitted Image and repro steps appended. I conf ...

Delta struct serialized fast arrays replicating new elements with no changelist

UE - Networking - Jun 14, 2021

There is a scenario where delta struct serialized fast arrays can replicate changes that introduce additional elements to the array, but without changelists containing the new data. This needs furt ...

Shader compiler errors when using enclosed local variables in a material while ray tracing is enabled

UE - Rendering - Architecture - RHI - Jan 23, 2020

A licensee is seeing an issue with a couple of post process materials after enabling ray tracing. While the materials presenting the issue fail to compile for different reasons, they both refernce t ...

Depth of field issues on Translucent Materials with Raytracing and DirectX12 enabled

UE - Graphics Features - Lumen - Oct 9, 2020

With DirectX12 and Raytracing enabled, translucent materials are not showing the correct depth of field.  Reported in version 4.25.3(CL 13942748). Tested and found in versions 4.25.3 and 4.24.3(C ...

Some materials render black on Iphone 6 series phones

UE - Platform - Mobile - Oct 6, 2016

Some materials are not rendering on iphone 6 series devices. They will render completely black on one device but not others in the same series. Replacing the material with a basic material renders o ...