Using the "Keep World" scale rule can result in incorrect relative location when attaching actors

UE - Framework - Components - Dec 9, 2022

This seems to happen due to a precision error when calculating the relative transform between the socket and the component being attached. Occasionally, one of the transforms will have a scale of (0 ...

Unable to edit double variable in property matrix

UE - Editor - Workflow Systems - Oct 2, 2023

Since UE5.0, cannot edit double variables in property matrix. In UE4.27, it worked correctly and could be edited from the property matrix. This is because double variables are not supported in SProp ...

The Gradient Paint Tool In Cloth Simulation Doesn't Work On Mac

UE - Simulation - Physics - Feb 28, 2020

The Gradient Tool rotates the camera on Mac instead of painting the Gradient End Value. I wasn't able to test in Main on a Mac. There were no issues on Windows in 4.23.1, 4.24.3 and 4.26 Main. Foun ...

Blueprint compiler doesn't always initialize struct consts correctly

UE - Framework - Blueprint Compiler - May 1, 2025

Blueprints currently don't support unsigned 64 bit ints, but they do support signed 64 bits. If a Blueprint uses a native struct variable that contains a uint64 property, it incorrectly assigns that ...

TSR and TAA history accumulation gets reset when taking viewport screenshots or when clicking outside the tree in the outliner

UE - Graphics Features - May 30, 2025

TSR (and TAA) history accumulation gets reset when taking viewport screenshots or when clicking on an empty area in the outliner (when a tree item is selected). This can cause an undesirable issue w ...

Mac - Inconsistent results for Lumen renders

TM - Rendering - Jun 3, 2025

Reported in SF [Link Removed] and [Link Removed] Users on Mac are reporting inconsistent rendering results for Lumen in image exports that do not include any settings changes. When exporting some ...

SSR Experimental Denoiser crashes when enabled using Vulkan

UE - Graphics Features - Apr 27, 2020

Enabled the SSR Experimental Denoiser using Vulkan causes the Engine to crash. This crash does not happen with DX11 or DX12. This happens on Linux and Windows (-vulkan). This was reported and teste ...

POST /v1/testdata API doesn't properly convert data to BSON

UE - Foundation - Horde - Server - Jun 24, 2025

Post: { "jobId": "685b12ad6765a5c9fefad260", "stepId": "a991", "key": "output-otem-job2", "data": { "Type": "Simple Report", "TestName": "EditorClientBoot", "Descript ...

NPC - Instances does not get updates from changes to the parent Niagara Parameter Collection in the editor

UE - Niagara - Oct 4, 2024

When an Niagara Parameter Collection (NPC) is selected as the parent Collection for an NPC Instance (NPCI), all of its current parameters are carried over to the NPCI with their current values as th ...

Crash when attempting to change the parent of a material instance constant through editor scripting

UE - Rendering Architecture - Materials - Apr 9, 2025

The built-in class "UMaterialEditingLibrary" provides various editor scripting functions related to creating and editing materials and material instances. One of these functions, UMaterialEditingLib ...