Crash reimporting a skeletal mesh with less Material IDs than on first import

NOTE: Does not occur in 4.16, entered this to find a fix for licensee to integrate. Error message: Assertion failed: (Index >= 0) & (Index < ArrayNum) [Link Removed] [Line: 633] Array index out o ...

[CrashReport] USpeedTreeImportFactory::FactoryCreateBinary()

UE - Editor - Content Pipeline - Import and Export - Sep 19, 2017

This is a common and longstanding SpeedTree import crash that has occurred since at least 4.14 for over 100 users. This seems to be the same issue as a previous Jira from 4.10 which was closed wit ...

NavLink Proxy CHILD ACTOR stops working in a Packaged and Standalone game

UE - AI - Oct 5, 2017

NavLink Proxy CHILD ACTOR stops working in a Packaged and Standalone game. Works as expected in PIE. Licensee Description: Force Rebuild on Load is not called and the nav links as child actors do ...

Mover | FStanceModifier adjustment teleport on Crouch/Uncrouch can fail when child components intersect world

UE - Gameplay - Player Movement - Mover - Feb 3, 2026

Context When crouching and uncrouching with Mover’s DefaultMovementSet, the pawn capsule’s half height is changed. This behavior mimics the CharacterMovementComponent. To ensure the pawn’s feet sta ...

Unable to build marketplace code plug-in

UE - Foundation - Cpp Tools - UnrealBuildTool - May 17, 2022

Fix for [Link Removed] sets the RuleAssembly in the Marketplace plugin to ReadOnly. This has prevented the plugin binaries from being compiled. Change the readonly flag as shown in the following co ...

[CrashReport] UE4Editor_SlateCore!SWidget::SlatePrepass() [swidget.cpp:493]

Tools - Dec 1, 2017

This is a common crash in the 4.18 release. The callstack is rather generic, and I have attached two logs but neither displays the error information. Users have also not provided any descriptions ...

Crash when building lighting while in PIE

UE - Graphics Features - Feb 21, 2017

NOTE: This issue is similar to (same callstack) as [Link Removed], however this issue is still occurring in 4.15.0. Error Message: Access violation - code c0000005 (first/second chance not availab ...

[AI] EQS incorrectly sorts when auto-sort in single-item mode when there is only one filtering and one scoring test.

UE - AI - EQS - Dec 14, 2021

EQS places a cheap filter as the last step of a query when using auto-sort for single item results if there is only one filter. Found via [Link Removed] which is quoted below:Environmental Query sys ...

FBX naming conflicts causing collision to not import correctly.

UE - Editor - Content Pipeline - Import and Export - Feb 17, 2025

For our static mesh pipeline we have group nodes in Maya that use the name of the asset. Under that we have a mesh that also has the name of the asset. We may also have collision as well so a typica ...

When using Subversion (SVN) and Lock's comment is Japanese outside SourceControl, parsing of xml fails and Status may become NotControlled.

UE - Foundation - Core - Jun 28, 2019

If user lock assets with Japanese comments outside source control, XML acquired in svn status may contain Japanese strings, and XML parsing may fail and become NotControlled. This issue does not oc ...