Static Lights with IES Profiles Will Bake an Incorrect Lightmap

UE - Graphics Features - Jan 3, 2019

When using an IES profile with a static light, the lightmap that gets baked will lose all detail of the IES profile. Example project attached. This doesn't occur in 4.19 CL# 4033788 Found in 4.20 ...

Crash When Material is Set to Deferred Decal with Emissive Decal Blend Mode and Forward Shading Enabled

UE - Graphics Features - Jan 25, 2019

When Forward Shading is enabled, if you create a material with their properties setup with the following:   Material Domain: Deferred Decal - Blend Mode: Translucent - Decal Blend Mode: Emissive T ...

Streaming Multiple Instances of the Same Landscape Actor All Have the Same GUID

UE - LD & Modeling - Terrain - Landscape - Apr 15, 2019

If a level contains a landscape actor, and if you stream multiple instances of that level into your map, you will get errors in the message log that the landscape actors have the same GUID. Found i ...

Editor crashes when adding a parameter to a material when using Forward Shading and DX12

UE - Graphics Features - Apr 24, 2019

Setting the default RHI for Windows to DX12 and enabling Forward Shading results in a crash when adding a texture sample parameter to a material. Found in 4.22 CL# 5660361 and 4.23 CL# 6074473 Wor ...

Breakpoints on nodes in deleted functions are not cleared

UE - Gameplay - Blueprint - Nov 16, 2018

Might be a simpler repro than this, but take a look at revision 1 of PreRolledBoxes in FortniteMain to see an asset affected by this. It was duplicated from StoreRoot which had breakpoints in some o ...

Overridden mesh values are lost when upgrading from 5.5.0/5.5.1 to 5.5.2 on blueprint skeletal mesh components

UE - Anim - Runtime - Jan 30, 2025

This issue is caused by the backout in 38341618.  The original code that went into 5.0 affects serialization by changing the UCS modified properties.  When upgrading, the override is lost because th ...

Performance issue with the material dock

TM - Tools - Oct 1, 2025

See video. Tested on 2025.2  In a project where you have a lot of materials, it take a long time to open the material dock. Here around 20 seconds. And that's at each time you want to enter it. Y ...

World position offset behaves differently when setting its value directly on the result node

UE - Rendering Architecture - Materials - Jul 8, 2024

The world position offset input of the result node does not behave consistently. There is an obvious visual difference between the setting it by connecting a float3 color constant, versus setting th ...

Editor movement control regression

Tools - Jul 8, 2015

Using Ctrl+Drag in 4.8 will not affect the location of selected actor if the viewport camera is facing away from selected actor. In 4.7.6 the actor would travel along the X axis even if the camera ...

Drastic increase in FBX import times from 4.9 to 4.10

Tools - Dec 9, 2015

The attached asset (including animation) takes 9 minutes to import in 4.10, where it takes 42 seconds in 4.8 and 4.9. You don't really notice this until you start to get up to larger assets or long ...