When importing an FBX with Combine Meshes = False, one uasset will be created for the collection of assets.

Tools - Feb 4, 2016

When importing a mesh, there is an option to Combine Meshes, which by default is checked. Unchecking this option will bring in the individually named parts contained in the FBX as unique objects in ...

[CrashReport] Assertion failed: Array index out of bounds - GetPhysicsTriMeshData() [modelcomponent.cpp:688]

UE - Simulation - Physics - Oct 30, 2017

This is a semi-common crash that has occurred since at least 4.17.1. The callstack is nearly identical to [Link Removed], which was fixed in 4.18.0, however the error message and source context are ...

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 ...

Assertion failed: (Index >= 0) & (Index < ArrayNum) when importing large Alembic file

UE - Editor - Content Pipeline - Datasmith - Importer - May 3, 2022

Regression testing done on //UE4/Release-4.27.2 CL-18427296 and this issue did occur. [Link Removed] [Link Removed] Below is snips of customers description and proposed workaround:Importing alembi ...

[UDN - 00707230] DetailLayoutHelpers ensure when using VisibleAnywhere Instanced properties

UE - Editor - Workflow Systems - Jan 11, 2024

From UDN Description Hello, there's an ensure that's firing in `DetailLayoutHelpers.cpp#137`: [Start code block] ensure(PropertyNodeMap.ParentProperty == CurObjectNode); [End code block]when ...

Crash when destroying a pawn on the client

UE - Networking - Jul 6, 2015

Crash when destroying a pawn on the client. Reproduced in 4.8.1 and Main (//depot/UE4/Promotable-CL-2610743). This is a regression: the crash does not occur in 4.7.6 Crash Report: [Link Removed] ...

Crash after creating a suboject for RootComponent if the actor is placed on the level

UE - Foundation - Cpp Tools - Hot Reload - Nov 6, 2020

The crash occurs when trying to assign a new value to RootComponent if the Pawn is already placed on the level Crash does not happen in  P4 //UE4/Release-4.25.3 CL 13942748 Other steps to reproduc ...

Unexpected behavior when Actor Parenting in the World Outliner of a WP map

UE - World Creation - Worldbuilding Tools - World Partition - Nov 23, 2021

Licensee reports the following in the UDN: There seems to be some other erratic behavior when using parenting in world outliner (i.e. drag and drop one actor on another one in world outliner).Since ...

POST /v1/testdata API doesn't properly convert data to BSON

UE - Foundation - Horde - Server - Jun 24, 2025

Post: { "jobId": "685b12ad6765a5c9fefad260", "stepId": "a991", "key": "output-otem-job2", "data": { "Type": "Simple Report", "TestName": "EditorClientBoot", "Descript ...

[CrashReport] UE4Editor_Engine!LoadSpecialMaterial() [unrealengine.cpp:1523]

UE - Graphics Features - Nov 10, 2017

This is a longstanding crash that has occurred for more than 200 users since at least 4.13. Based on user descriptions this appears to permanently corrupt a project. User DescriptionsI just turned ...