Cumulative Patching does not work with Pak signing

UE - Foundation - Feb 20, 2024

Cumulative patching is implemented by copying the generated pak files during staging of the base and each patch to the Releases directory. When creating a patch, all of the pak files from the releas ...

Option "Use Mouse for Touch" does not work correctly when running the game in "Standalone" or "New Editor Window (PIE)" modes: Virtual joystick does not appear and mouse cursor is incorrectly hidden while captured.

UE - Gameplay - Input - Apr 1, 2025

The Editor provides option "Project Settings – Engine – Input – Mouse Properties – Advanced – Use Mouse for Touch" to allow testing virtual joysticks and other touch controls with the mouse. When ru ...

If a child blueprint class has an Instanced/EditInlineNew object property, that property will always be detected as changed by the property editor (i.e. it will show a "Revert" arrow on that property), even if its properties are identical to the parent.

UE - Framework - Blueprint Editor - Dec 17, 2025

Context: Blueprint classes can use Instanced/EditInlineNew object property specifiers to create and edit subobjects directly in the editor. Problem: If a child blueprint class has an Instanced/Edit ...

Possible data loss/corruption when loading levels in editor

UE - Gameplay - Jul 18, 2018

Reported behavior: Given Level_A which contains object_X, where object_X references Level_BDeleting object_X causes AssetRenameManger to check if we need to patch up other levelsLevel_B is load ...

OSVR fatal error while playing in -game

UE - Platform - XR - May 6, 2016

Found on: //UE4/Dev-VR CL-2967563 About 1/6th of the time I'd start a -game instance and go in to stereo on the OSVR, the game would seemingly just close itself. I say close as opposed to crash, si ...

Editor crashed when opening TM-MeshPaint in QAGame

UE - Graphics Features - Jan 20, 2017

While reviewing [Link Removed] test case, I hit the following crash opening the TM-MeshPaint level. On first attempt shaders were compiling, on attemps after, editor crashes much faster. ...

BP - Nativization will fail at cook time if a BP class and a User-Defined Structure reference each other.

UE - Gameplay - Blueprint - Apr 20, 2017

Note: This happens with "Exclusive" nativization mode as well. This occurs because the nativized UDS 'GetDefaultValue()' method is generated into a .h file rather than a .cpp file. This creates a c ...

Loading Duplicated Level via Python API Crashes Editor

UE - Editor - Workflow Systems - Feb 16, 2023

When called from Python, in 5.1 the load level invocation results in a kernel panic style crash of the editor, with a message about the map leaking memory and not being able to be garbage collected ...