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

UE - AI Workflows - 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 ...

Navmesh doesn't work in a Packaged Build if it was placed in a Sublevel

UE - AI - Oct 19, 2018

Once packaged, a persistent level is unable to create navmesh data properly if the navmesh bounds volumes are only present in its sublevels. The issue can be traced to the UNavigationSystemV1::IsThe ...

When change sequence struct parameter, the editor crash.

UE - Anim - Sequencer - Jul 31, 2017

when change sequence struct param, the editor is carash. It occurs in the case of using "Sound Wave", but the same problem occurs when "Sound Cue" is used. Attach application log, and crash dump fil ...

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 ...

[CrashReport] Mac Metal crash - FSceneRenderer::RenderDistortion()

UE - Graphics Features - Aug 29, 2017

This is a somewhat common Mac crash occurring since 4.15 and into 4.17.1. Users have not provided any descriptions of their actions when the crash occurred. This specific callstack was previously ...

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 ...

StateTree: While editing State Parameters or exposed properties of a Condition/Task, an ensure() fires when editing inputs of a Property Function bound to an array element

UE - AI - StateTree - Mar 5, 2026

Consider an array property that can be edited in the StateTree editor. This can be a State Parameter or an exposed property of a Condition or Task, for example. Each element of the array can be boun ...

Blueprint with large amount of macros crashes on compile

UE - Gameplay - Blueprint Compiler - Jan 30, 2018

Blueprint compile is crashing in a BP with a large number of macros ...

Adding a custom plugin to a code project that is in the root location of a drive will result in an error stating that the plugin was found in two locations

UE - Foundation - Cpp Tools - Plugin System - Nov 25, 2016

Creating a new custom plugin in the root location of a drive results in the project being unable to open or build. An error message appears that states that the plugin was found in two locations, an ...

Android crash a couple minutes into StrategyGame

UE - Platform - Mobile - Mar 8, 2016

This didn't occur on iOS; so far this has only been tested in StrategyGame The device this occurred on was Nexus5X_6713_Adreno 418, 6.0.1 It did not occur on: iPad Mini 4_6242, 9.2.103-08 14:12:0 ...