Nested code component causes ensure in blueprint's child blueprint

UE - Gameplay - Blueprint - Aug 25, 2017

When a component class (base) contains a component property (Nested) adding the base component to a blueprint and changing the position of the component will update the base and nested components as ...

[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 ...

Revision Control > View Changes: Request for changes to Revert File and Unsaved options

UE - Editor - Workflow Systems - Sep 22, 2025

1. Objects in the Unsaved list cannot be discarded, only saved. The only options to discard changes are restarting UE or manually locating each resource and clicking Reload. This becomes extremely c ...

Package fails after adding DesktopPlatform to public module dependency list

UE - Foundation - Core - Apr 6, 2017

Adding DesktopPlatform to the PublicDependencyModuleNames.AddRange() section of the Project.Build.cs file causes the project to fail packaging with the following error (full package logs in callstac ...

Crash on checking event track key property after setting static mesh reference element

UE - Anim - Sequencer - Oct 19, 2017

Event track key with a structure containing staticmesh reference. Setting the staticmesh then reopening the property crashed the editor. ...

UPrimitiveComponent mouse events when underneath Slate widgets not correct

UE - Editor - UI Systems - Slate - Jan 7, 2016

Licensee is adding a widget to the viewport overlay via AddViewportWidgetContent(). The widget receives mouse input when hovered. They return unhandled from all their widget's onmouse functions and ...

Translucent Materials and Atmospheric Fog Appear Black or Pink on Mac

UE - Graphics Features - Jan 3, 2018

I tested this on a Mac Pro in UE 4.15, 4.16, 4.17, and 4.18. As a possible workaround for the fog issue, I've discovered that setting Atmospheric Fog > Lighting > Disable Ground Scatter to "True" wi ...

Camera Switcher Import option not functioning properly

UE - Anim - Sequencer - Oct 22, 2019

In UE 4.20 we got a feature that let you import a FBX file that contains cameras with a camereaswitcher to create a "camera cut track" within sequencer. From the release notes of 4.20: https://docs ...