[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 - Open File Formats - 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 ...

Users Unable to create C++ Projects

UE - Foundation - Core - Mar 6, 2015

2nd AH post with the same issue: https://answers.unrealengine.com/questions/183441/cant-load-c-projects.html Multiple people have reported not being able to create a C++ project. Creating a Bluepr ...

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

UE - Editor - Verse Class Editor - 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 ...

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 ...

Wrong WPO motion vectors due to Periodic World Space node

UE - Rendering - Features - May 13, 2026

We've noticed smearing in grass due to wrong motion vectors. This appears to be caused by lack of previous frame support in the periodic world space node. This is how we fixed it: In MaterialTempl ...

[CrashReport] Crash on Mac related to editor close

UE - Platform - Apple - Jun 6, 2017

This is a long-standing Mac crash that occurs with low frequency, but has affected more than 500 users since it started (possibly in the 4.11 release) It has recently been experienced internally by ...

Event Tick is not running once packaged

UE - Gameplay - Components - Jul 20, 2015

Event Tick works when it's running on Windows however once it's packaged or even launched onto all platforms, the event tick does not work as anticipated. This happens on all platforms. *Project ca ...

[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 ...