Material Parameter Collections are not working on Android v 5 phones from 4.11

UE - Platform - Mobile - Feb 9, 2016

Material Parameter Collections are not successfully passing stored values into Materials when packaged for an Android Phone with an OS version of 5. Both version 4 and 6, correctly use the MPC.Test ...

FStateTreeExecutionContext::GetDebugInfoString() outputs wrong info and crashes when using linked state trees

UE - AI - Debugging - Apr 17, 2025

When using State Trees, the AI Debugger can be accessed during play to show information about their current execution state. If a behavior tree is currently in a state that references a linked tree, ...

Crash when Copy/Pasting from Older UE Versions

UE - Editor - Workflow Systems - Mar 17, 2023

When copy/pasting scene objects from older Unreal versions into Unreal 5.1, the editor will crash. ...

ResetToDefault() incorrect behavior with multiple components selected with different defaults

UE - Framework - Blueprint Editor - Oct 2, 2023

In the blueprint editor when selecting multiple components and resetting a property that exists on both components to its default value, when the components had different default values the editor r ...

Niagara - When Interpolated Spawning is disabled, the first frame of each particle unexpectedly does not take into account the Particle Update stage

UE - Niagara - Feb 28, 2025

Foreword: Even if the behavior described here is by design, it is rarely (if ever) expected or desired. This was discussed and agreed to be treated as a bug. Explanation below. When interpolated sp ...

Forced reboot launching editor the first time

UE - Foundation - Cpp Tools - May 30, 2018

Note that before I tried running the editor via the Launch button, I just happened to run the Editor exe directly, and this did not repro then. After my PC rebooted I tried to reproduce it again an ...

LODs screen sizes in legacy assets are incorrectly converted to all have the same value on load

UE - Editor - Content Pipeline - Sep 11, 2025

When loading a static mesh asset created in an old version of Unreal (e.g. 4.10), all LODs have their Screen Size property set to the same value (approximately 1.5). This happens because the static ...

Screen Space Ambient Occlusion Artifacts

Docs - Samples - Apr 3, 2015

Flickering occurs when using the Post Process Ambient Occlusion (Screen Space AO). This is more noticeable when using stronger values entered into the AO fields. I checked these settings in both 4 ...

Get All Actors of Class is failing to report at Event Begin Play in a streamed level

UE - Gameplay - Sep 3, 2015

Get All Actors of Class is failing to report at Event Begin Play in a streamed level. Test project attached. This is a regression: did NOT occur in 4.8.3. Reproduced in 4.9.0 binary and Main (2678 ...

UV Rotation does not work for video materials

TM - Rendering - Dec 9, 2024

The rotation parameter of video materials does not function in Twinmotion 2024.1.2 and Twinmotion 2025.1 PR. Adjusting the slider does not have any effect. Feature last worked in Twinmotion 2023.2 ...