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 - 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 ...

[CrashReport] UE4Editor_ShaderCore!FVertexFactory::Set() [vertexfactory.cpp:190]

UE - Graphics Features - Nov 17, 2017

This is a common crash in the 4.18 release. It is the exact same callstack (and crashGroup) as in [Link Removed], although that Jira had specific repro steps and was confirmed fixed in 4.18.0. The ...

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 ...

FBX naming conflicts causing collision to not import correctly.

zComponent - Archive - 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 ...

Water: WaterZone GPU data packed densely in FWaterViewExtension::UpdateGPUBuffers but indexed by sparse WaterZoneIndex, causing water to disappear

UE - Graphics Tools - Terrain - Water - Oct 14, 2026

Summary Water can sporadically disappear in World Partition maps that have multiple spatially loaded AWaterZone actors. FWaterViewExtension::UpdateGPUBuffers() builds the WaterZoneData and WaterZone ...

[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 ...

[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 ...