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 ...

OpenXR Remoting fails to attach actions to remoting session in 4.27

UE - Platform - XR - Jul 13, 2021

Regression from 4.26 where actions fail to bind when remoting in 4.27 Repro: using the Microsoft OpenXR Extensions plugin here:https://github.com/microsoft/Microsoft-OpenXR-Unreal/tree/main/MsftOpe ...

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 ...

In the level editor, when configuring a component that is part of an actor blueprint, adding entries to a TMap with C++ enum keys results in duplicate keys and an incorrect warning popup.

UE - Editor - Workflow Systems - Jan 22, 2026

Note: This started happening in UE 5.4 and persists up to latest. It is probably related to [Link Removed] Closed ([Link Re ...

[CrashReport] Access Violation - UModelComponent::GetPhysicsTriMeshData() [modelcomponent.cpp:673]

UE - Simulation - Physics - Oct 2, 2017

This is a trending crash coming out of the 4.18 Previews. Users have not provided any descriptions of their actions when the crash occurred. The callstack is similar to [Link Removed], which was ju ...

Using Execute Console Command in a custom Game Instance causes Standalone Game to crash

UE - Gameplay - Blueprint - Jan 15, 2015

Using Execute Console Command in a custom Game Instance causes Standalone Game to crash. Also occurs in 4.6.1: CL-2386410 and 4.7 Preview: CL-2403078 Crash Report: [Link Removed] Call Stack:UE4Ed ...

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 ...