Updates to DesiredFocusWidget for a UserWidget are not propagated to existing instances of it inside the WidgetTree of other widgets

UE - Editor - UI Systems - Nov 17, 2025

This issue has been reproduced in UE 5.3 to 5.7 and source versions. A repro project is available. Below are the findings from an initial investigation of the problem. Normally, when a UserWidget p ...

Crash when Matinee with 2 Event Tracks stopped from one of the Event Tracks

Tools - Mar 16, 2015

When stopping a Matinee from an Event Track via the level blueprint, if you have 2 Event Tracks the editor will crash. Also Reproduced in Main Promotable-CL-2479729 ...

Editor crash when shader debugging enabled including r.shaders.optimize=0

UE - Rendering - Architecture - Shaders - Jun 23, 2024

The editor crashes when activating cvar options for shader compilation and debugging. ...

Loading Duplicated Level via Python API Crashes Editor

UE - Editor - 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 ...

Unable to create installed build with iOS support from PC

UE - Foundation - Core - May 3, 2017

Attempting to build a local binary engine from a source engine will fail when iOS support is enabled in the setup process. Command line argument (ran from Engine/Build/BatchFiles folder location): ...

New VR-Basic level triggers Metal validation layer assertion

UE - Platform - Apple - Mar 16, 2020

This was discovered externally and reported on UDN here: https://udn.unrealengine.com/questions/563268/mac-editor-crash-when-disable-ambient-occlusion.html ...

Importing a New Substance Preset will crash the engine

UE - Foundation - Core - May 13, 2015

With the Substance plugin installed and when you try to import new preset data into the Substance Graph Instance, the engine will crash ...

Crash when launching Google VR project

UE - Platform - XR - Dec 12, 2016

Attempting to launch a packaged Google VR game on android causes the game to crash. This has occurred on two other devices. This occurs in Main as well as Dev-VR. ...