Mesh reduction modules selection aren't properly applied on engine restart

UE - World Creation - Worldbuilding Tools - May 4, 2023

Recent changes in the MeshReductionManagerModule::StartupModule() have introduced issues where it won't respect what reduction modules have been set in the config file. This is a big issue for plugi ...

can not load all actors when load level with ULevel::LoadAllExternalObjectsTag

UE - World Creation - Worldbuilding Tools - Jun 25, 2024

the udn link:https://udn.unrealengine.com/s/question/0D5QP00000OxDLH0A3/%E9%80%9A%E8%BF%87%E4%BB%A3%E7%A0%81%E6%88%96%E8%80%85%E8%93%9D%E5%9B%BE%E8%8A%82%E7%82%B9%E5%A4%8D%E5%88%B6%E5%85%B3%E5%8D% ...

UConsole HistoryBuffer no longer writing to disk in packaged builds

UE - CoreTech - Sep 7, 2023

We started running into issues with the console history not saving after upgrading to 5.2.1. The console history (as in the commands last input into the in-game console) is no longer being saved bet ...

Lightmass GI doesn't work with Material-based color changes

UE - Graphics Features - Sep 4, 2015

A licensee is having trouble getting the visual results they want because Lightmass doesn't seem to handle color changes from materials. They are seeing this in 2 cases: (See attached images and tes ...

[CrashReport] Crash while snapping multiple actors at once

Tools - Aug 29, 2017

Crash occurs when selecting all actors and pressing "End" to snap them to the floor. This doesn't occur if you create a blank map and add a few actors to it. The specific conditions may need to be ...

[CrashReport] UE4Editor_Engine!FMaterialShaderMap::GetMeshShaderMap() [materialshader.cpp:2395]

UE - Graphics Features - Mar 30, 2018

User comments in crash group:Duplicating material and switched it cause i have to use itChanging a landscape material.I just import World Machine landscape with multi-layered.Crash when reaching 16 ...

Control Rig - Undo doesn't function correctly with proxy and multi bone controls

UE - Anim - Rigging - Control Rig - Oct 26, 2025

Issue from my Technical Animator where the undo operation in Control Rig doesn't work as expected on Proxy Controls. He has recreated the issue using the "Control Rig Samples Pack" and recorded a vi ...

[CrashReport] UE4Editor_Engine!FSoundConcurrencyManager::RemoveActiveSound() [soundconcurrency.cpp:545]

UE - Audio - Oct 5, 2017

This is a common crash that has occurred since at least 4.15. The callstack is similar to [Link Removed], which was resolved in 4.16. User Descriptionsdisable sound concurrency Source Context 5 ...

Strange intermittent CCD behavior on constrained physics bodies

UE - Simulation - Physics - Oct 23, 2019

There is some strange issue with CCD where constrained CCD objects can get velocity nulled when hitting things while constrained, its very hard to reproduce normally in engine but happens often in V ...

GAS and single process PIE: modifiable static variables accessed by server and client

UE - Gameplay - Gameplay Ability System - Nov 16, 2022

See: UAbilitySystemGlobals::HandlePreLoadMap GAS features static variables that are modified by both server and client, thus result in issues in single process PIE where they access the same memory ...