If using Launcher build, Advertising Identified (IDFA) code for iOS can NOT be disabled by project settings

UE - Platform - Mobile - Jun 18, 2019

By [Link Removed], user can disable IDFA without customizing engine code. But, if using Launcher build, the added settings( Enable Advertising Identified(IFFA) ) does NOT work correctly. Because eng ...

Cook fails when a MetaSound Source object is referenced utilizing FObjectFinder in C++

UE - Audio - MetaSounds - Apr 27, 2022

Android Cook fails when a MetaSound Source object is referenced utilizing FObjectFinder in C++ Repro Rate: 3/3 UATHelper: Cooking (Android (ASTC)): LogInit: Display: LogMetaSound: Error: Target int ...

UNetDriver server-side hitch results in ActorInfo->NextUpdateTime far into future

UE - Networking - Feb 16, 2024

A high UWorld::Tick DeltaSeconds (i.e. GameThread hitch) results in a high UNetDriver::TickFlush DeltaSeconds. This DeltaSeconds can high (many seconds) if the hitch is long. This value then affects ...

Animation Orientation does not Auto-Convert to UE4 Coordinates when Reimporting

OLD - Anim - Nov 23, 2015

Animation orientation does not auto-convert to UE4 coordinates when reimporting the same way it does when importing the same animation as a new import. In other words, a run animation generated from ...

BulkData Async loading remains in memory

UE - Foundation - Core - Oct 26, 2016

Gil's new loading path may already walk away from this issue. But here's some thing I tested locally if we want to fix this. A simple way to fix is to simply add BulkDataAsync.Deallocate(); ResetA ...

Editor Crashes on Opening After Deriving C++ Class from Another Class

UE - Foundation - Cpp Tools - Hot Reload - Sep 13, 2017

After deriving a C++ class from another class and then closing the editor, the project will crash when reopened. This crash will continue until the project files are regenerated and the project is r ...

Editor reports crashes and terminates for exceptions that would otherwise be cleared by structured exception handlers

UE - Foundation - Core - CrashReportClient - Jun 8, 2020

In 4.25.1, I added a vectored exception handler to capture unhandled exceptions to the Editor process. This handler runs too soon. It doesn't let the structured exception handlers run first where ma ...

[CrashReport] Assertion failed: NewWorld | UE4Editor_Engine!UEngine::LoadMap()

UE - Gameplay - Nov 2, 2017

This is a common and longstanding crash that has occurred since at least 4.15. Originally this was being tracked under [Link Removed] due to sharing the same callstack, but that had specific repro ...

Crash Opening Editor with Vulkan - Fatal Error - RenderingThread.cpp

UE - Rendering Architecture - RHI - Mar 15, 2019

Editor crashes when opening to project browser on Linux. Fatal error: [File:D:\Build\++UE4\Sync\Engine\Source\Runtime\RenderCore\Private\RenderingThread.cpp] [Line: 819] Rendering thread exceptio ...

Changes to Instanced Properties default value on BP not propagated to placed actors in the opened level

UE - Foundation - May 15, 2025

In UE versions 5.4 and onwards (as of CL 42589677 in Main), when an Instanced UObject property is defined in an Actor Blueprint, modifying the default value in the Blueprint does not propagate the c ...