When PCH is Disabled, Error Occurs in VulkanGenericPlatform.h at Android Build

UE - Graphics Features - Dec 6, 2018

If disable PCH in Target.cs, an error will occur when building for Android. The log is as follows. LogPlayLevel: Error: D:/Build/Release-4_21_0/Engine/Source/Runtime/VulkanRHI/Private/Android/../Vu ...

[CrashReport] Mac crash - UE4Editor-Slate.dylib!PrepassWindowAndChildren(TSharedRef<SWindow, (ESPMode)0>)

UE - Platform - Apple - Oct 27, 2017

This Mac crash originally occurred in 4.15 around March 2017, then decreased in frequency during 4.16 and 4.17. It may be starting to trend again in 4.18. There is one record of this occurring in 4 ...

CRITICAL: Regression: CRASH: SHOOTERGAME: Client crashes when using ServerTravel command

UE - Networking - Sep 17, 2014

Update (5/4/15): New repro steps using Main (//depot/UE4/Promotable-CL-2535351): 1. Create a new Blueprint project 2. Create 3 new Levels: MainMenu, Lobby, and Level 3. Create 3 new GameModes: Main ...

Deadlock in UPhysicalAnimationComponent::UpdatePhysicsEngineImp

UE - Runtime - Simulation - Sep 13, 2023

Deadlock in Chaos during PIE; the main thread is in USkeletalMeshComponent::HandleExistingParallelEvaluationTask waiting for a task to complete, and a worker thread is running that task and is in US ...

Bloated instruction counts in the material editor causing long compiles

UE - Graphics Features - Apr 17, 2019

artists are dealing with greatly increased iteration times due to long shader compiles when working in the material editor. This has regressed over time as we add more features to the point were wor ...

HTTP If-None-Match response code is incorrect on Macintosh

Tools - Sep 22, 2016

Macintosh implementation for HTTP requests handle If-None-Match against ETags differently than Windows implementation. ...

Anim Notify States are ended when CustomTimeDilation is set to zero

UE - Runtime - Animation - Oct 12, 2022

UDN link: https://udn.unrealengine.com/s/question/0D54z00008BEDfJCAX/set-actor-time-dilation-to-0-during-a-animation-notify-state-cancel-it?fromCase=1 Notify gathering functions (e.g. UAnimSequence ...

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 ...

DLC Package content isn't recognized when using RequestAsyncLoad

UE - Foundation - Core - May 24, 2016

Attempting to load dlc assets with RequestAsyncLoad function results in the assets not being recognized. ...

iOS Shipping Build using std::thread crashes on launch

UE - Platform - Mobile - Jun 2, 2017

A user is reporting that using the following code in a GameMode class causes shipping iOS packages to crash on launch:void ANOGSSDKGameModeBase::StartPlay() { std::thread([](){ std::clog << "THRE ...