Skelmesh Bake Materials doesn't remove old materials from slots

UE - World Creation - Worldbuilding Tools - Merge Actor - Mar 24, 2021

When an LOD get materials reduced to one with Bake Materials, it doesn't delete the extra slots on the LOD. So if starting with 10 slots on the skelmesh, then baking, slot 1 gets the newly baked mat ...

An array of structures variable has its values reset when the structure is modified without recompiling the blueprint

UE - Framework - Blueprint Compiler - Apr 2, 2021

An array of a structure that has been modified without the array's blueprint being complied results in the values of the array element being reset. Compiling each blueprint that has the array of str ...

Two-Sided Material option is initially greyed out and inaccessible when creating a Material Instance

UE - Rendering Architecture - Materials - Jun 9, 2021

When attempting to change the option for Two-Sided Material for a Material Instance, the option is initially greyed out and you cannot change the value. However, if you close out of the Material Ins ...

Override Parameters in the details section of the editor do not slice smoothly when dragging with mouse

UE - Niagara - Apr 6, 2022

Sliding a value within the override parameters in the details panel of the editor, the slider will get "stuck" after sliding to one value and it stops working. This occurs with any slider within the ...

Volumetric lightmap + stationary light has missing shadows

UE - Rendering Architecture - Sep 5, 2023

Primitives with the "Lightmap Type" set to "Force Volumetric" are not shadowed correctly. Issue dates back to at least 4.27.2. As a workaround, making FLightCacheInterface::GetStaticInteraction al ...

Dark square appears in hair in direction of spotlight when shadows disabled

UE - Graphics Features - Sep 18, 2024

A dark square appears in the direction of a spotlight on hair when the spotlight has no shadow. [Image Removed] In UE 5.4 the dark square is visible when the spotlight has no shadow, and a light s ...

Additives using Frame From This Animation as the Base Pose Type fail to retarget correctly

UE - Anim - Rigging - Retargeting - Feb 13, 2025

Additive animations that use a frame from their own sequence as a base pose are initially broken when retargeted.  Users have to refresh the properties that select the base pose in order to fix the ...

GPU Lightmass no longer works with cascaded shadow maps

UE - Graphics Features - May 29, 2025

Since Unreal Engine 5.5 stationary lights have stopped working with GPU Lightmass when using Cascaded Shadow Maps. With Virtual Shadow Maps enabled on the project, GPU Lightmass works. This issue d ...

[CrashReport][GPU Crash] UpdateRadianceCaches

UE - Graphics Features - Nov 19, 2024

A GPU crash may occur during UpdateRadianceCaches. No known repro exists. Additional details in comments. Latest version: ++UE5+Release-5.5-CL-37670630 Platform: Win64 [Windows 11 (24H2) [10.0.261 ...

Crash calling destroy actor for Geometry Collection while it's simulating

UE - Simulation - Physics - Destruction - May 12, 2020

Crash occurs when user call Destroy Actor on a Geometry Collection Actor. This seems to only occur while the actor is simulating. If called while on the ground, it doesn't seem to occur. ...