Component default data can be lost for a non-nativized Blueprint class that inherits the component from a nativized parent Blueprint class.

UE - Gameplay - Blueprint - Sep 5, 2018

This is a regression that was introduced by the fix for [Link Removed]. The fix makes an invalid assumption that instances of components whose archetypes are inherited by a non-nativized child Blue ...

Project launch options flicker between available and unauthorized/locked

Tools - Aug 20, 2018

Project launch options flicker between available and unauthorized/locked Unsure what causes this, but I have hit the issue twice. Another person has also seen this on their machine. I was able to ...

Actor Component Replication Not Working on Dynamically Spawned Components in Blueprint

UE - Networking - Aug 7, 2018

Actor components that are spawned dynamically through Blueprint are not being properly replicated to the client.  Found in 4.20 CL# 4233996 and reproduced in 4.21 Main CL# 4258917 Unable to test i ...

Widget With Spinbox Crashes When Destrcutor Is Called With Multithreaded Destruction Enabled

UE - Foundation - Core - UObject - Feb 28, 2020

When a widget with a spinbox is calls it's Destructor with "Multithreaded Destruction" enabled the engine crashes. I have tested in 4.23.1, 4.24.3, and 4.26 Main with "Multithreaded Destruction" dis ...

Alpha blending is done twice when using RenderOpacity of RetainerBox's parent slot

UE - Editor - UI Systems - UMG - Feb 10, 2023

Licensee reported that alpha blending is done twice in the code below, and the fix below seems to fix it. .\Engine\Source\Runtime\UMG\Private\Slate\SRetainerWidget.cpp From:const FLinearColor Compu ...

Crash in DX12 UpdateTexture2D

UE - Graphics Features - Jan 24, 2017

RHIUpdateTexture2D uses the wrong size for the per-row memcpy, which means we can't support passing in an offset within a larger image in the SrcData pointer (doing so will result in an access viola ...

Procedural Sounds Dropping First Samples

UE - Audio - Oct 26, 2015

When playing a sound with the bProcedural = true option enabled. The associated sound will then drop samples when played. The licensee who originally reported the issue actually has provided a fix i ...

Error when quitting Launch on session - A null object was passed as a world context object to UEngine::GetWorldFromContextObject().

UE - Gameplay - Jun 20, 2017

The following errors occur when the user quits a Launch On session from the editor:LogPlayLevel: QAGame: [2017.06.20-16.26.03:085][292]LogScriptCore: Error: Script Msg: A null object was passed as a ...

All console variables overridden in Movie Render Queue are set to 0 after the render queue runs

UE - Anim - Sequencer - Aug 4, 2020

All console variables overridden in Movie Render Queue are set to 0 after the render queue runs. It's because all cached previous console variables are reset to 0 just before they are written back ...

Building development version on Linux fails due to iOS folder structure

UE - Platform - Linux - Jun 26, 2017

In the default Linux folder configuration, Engine/Source/Runtime/Core/Public contains two folders, iOS and IOS. The iOS folder contains the files IOSCriticalSection.h and IOSCriticalSection.h while ...