When importing multiple meshes at once and change the Uniform Scale meshes import at different sizes

UE - Editor - Content Pipeline - Import and Export - Sep 21, 2017

When a large quantity (about 50 in this case) are imported simultaneously, and the Import Uniform Scale is changed to any other number besides 1, random meshes differ in size. This happens regardles ...

GPU Lightmass ignores IES Profiles on Static Lights while building lighting

UE - Graphics Features - Jun 8, 2022

This is a regression tested in //UE4/Release-4.27 CL#18319896 GPU Lightmass ignores IES Profiles on Static Lights while building lighting. Tested with different Global Illumination and Reflection s ...

Runtime Virtual Texture rendering can allocate more FRDGBuffers than expected

UE - Rendering Architecture - Dec 10, 2024

When rendering runtime virtual texture pages without throttling (when r.VT.MaxUploadsPerFrame is high or during Movie RenderQueue captures) the number of FRDGBuffers allocated by the Render Graph Bu ...

[CrashReport] UE4Editor_CoreUObject!FUObjectArray::AllocateSerialNumber() [uobjectarray.cpp:307]

UE - Editor - Content Pipeline - Import and Export - Sep 20, 2017

This is a somewhat common crash in 4.17. Users have not provided any descriptions of their actions when the crash occurred. Source Context 304 int32 FUObjectArray::AllocateSerialNumber(in ...

Enum with "MAX" element at other than the last element removes user defined last element

UE - Foundation - Core - Oct 18, 2019

FNativeClassHeaderGenerator::ExportEnum produces this behavior. If an enum has “MAX” somewhere in the array, it removes last element. I tested my code to fix the issue.// code placeholder bool UE ...

Montage Editor: Mouse Wheel Cannot Scroll to the Bottom of notify section when there are many track.

UE - Anim - Runtime - Jul 21, 2025

When a large number of notify tracks are added in the Montage Editor, the mouse wheel scroll does not allow the user to reach the bottom-most tracks. Only by manually dragging the scrollbar can the ...

Renaming a Blueprint interface asset doesn't update the ImplementedInterfaces list in the Blueprint editor's Class Settings tab

UE - Gameplay - Blueprint Editor - Nov 13, 2023

There is no UI refresh for the Implemented Interfaces list in the Blueprint editor UI after a Blueprint Interface asset is renamed in the Content Drawer. Consequently, the interface cannot be remove ...

Cloth paint update issues

UE - Simulation - Physics - Jan 7, 2020

Activating and Deactivating Cloth Paint marks the skeletal mesh as dirty, even if no values were painted and there is no transaction in the Undo History. Painting Max Distance values from non-zero ...

Destroying a welded actor is causing an Array index out of bounds crash on 5.6

UE - Simulation - Physics - Jul 30, 2025

Destroying a welded actor is causing an Array index out of bounds crash on 5.6. The licensee has provided a repro project that reliably causes a crash whenever the spawned actor is destroyed. There ...

Navigation System is gathering navigation bounds too early

UE - AI - Aug 6, 2015

In GameInstance.cpp when the Navigation System is created it calls... UNavigationSystem::InitializeForWorld This in turn ends up calling... GatherNavigationBounds(); This goes through all ...