A build may fail in Visual Studio if a space is added after the # in an include pre-processor instruction to allow a struct in one header file to reference a struct in the other

UE - Foundation - Core - Sep 23, 2016

A project building in Visual Studio will sometimes fail with the error Unrecognized type 'FBar' - type must be a UCLASS, USTRUCT or UENUM. This can occur in situations where one struct was reference ...

Mesh painting on staticmesh doesn't always apply Colors to All LODs

UE - Editor - Content Pipeline - Asset Build - Apr 18, 2022

See the video [Link Removed] ...

Actor Component properties can become "linked" across multiple Blueprints after a hot reload

UE - Gameplay - Components - Dec 3, 2018

If code in an Actor Component class is changed (eg. a new UPROPERTY is added) and a hot reload is performed to implement the changes, the properties in the component can become linked across any Blu ...

Crash When Enabling SSAO Smoothing with MSAA Enabled

UE - Graphics Features - Sep 12, 2019

The Editor is crashing when enabling SSAO while MSAA is enabled.  Found in 4.23 CL# 8386587 and 4.24 CL# 8569829 ...

Properties not serialized when moving actor/component depending on unrelated specifiers

UE - Gameplay - Blueprint - Sep 25, 2023

When an actor is moved on the level editor viewport, it is reconstructed along with its components, which at first makes their properties reset to their default state. Thankfully, this does not happ ...

Control Rig settings are not retained between editor sessions or carried into deployed game

UE - Anim - Rigging - Control Rig - Jun 10, 2020

Control Rig settings are not retained between editor sessions or carried into deployed game ...

[CrashReport] UE4Editor-Core!static void PureCallHandler() [WindowsPlatformMisc.cpp:477]

UE - Foundation - Core - May 8, 2020

Generated from CrashReporter Error Message: Fatal error: [File:D:/Build/++UE4+Licensee/Sync/Engine/Source/Runtime/Core/Private/Windows/WindowsPlatformMisc.cpp] [Line: 475] Pure virtual function bei ...

Race condition in full builds of UE4 engine source

UE - Foundation - Cpp Tools - UnrealBuildTool - Sep 26, 2019

This is a race condition caused by how "Clean.bat", a batch file used during rebuilds, tries to manually rebuild the UnrealBuildTool project when it runs. This causes a spam of UnrealBuildTool build ...

Mobile Previewer: Safe Zone Invalid Until Window Resize

UE - Platform - Mobile - Jul 12, 2021

When the Mobile Previewer loads, the Safe Zone widget is not working properly at startup, and requires a window resize to update to the correct Safe Zone. ...

Using dynamic bindings in a code class will result in the bindings becoming a permanent part of any Blueprint created from that class if a hot reload is performed.

UE - Foundation - Core - Mar 26, 2015

If dynamic bindings are being used in a custom code class from which Blueprints are derived, any hot reload will make the bindings a permanent part of the Blueprint and they cannot be removed or cha ...