Crash when removing and re-adding instances to an InstancedStaticMeshComponent with PerInstanceCustomData.

UE - World Creation - Worldbuilding Tools - Jan 22, 2026

When using an InstancedStaticMeshComponent with PerInstanceCustomData, the number of float elements in the "Custom Data" array should always be equal to NumCustomDataFloats multiplied by the number ...

Local binary build fails for iOS platform.

UE - Foundation - Core - Oct 5, 2017

Attempting to create a local binary build of the Engine for the iOS platform using BuildGraph is currently failing. While trying to build UHT for Mac using a remote build, the build fails because it ...

Crash calling user-function in non-editor

Tools - Apr 27, 2020

Crash occurs when attempting to call native Pre-Construct in the attached project. ...

Delta struct serialized fast arrays replicating new elements with no changelist

UE - Networking - Jun 14, 2021

There is a scenario where delta struct serialized fast arrays can replicate changes that introduce additional elements to the array, but without changelists containing the new data. This needs furt ...

Crash when removing cloth apb's assigned to asset

UE - Simulation - Physics - Character - Apr 27, 2016

When removing already assigned cloth asset from a skeletal mesh it will crash the editor. I was able to reproduce this with the Owen asset from Content Examples, but was unable to get it to work fro ...

Net Cull Distance does not work with Pawn only Character

UE - Gameplay - Player Movement - May 4, 2015

Licensee also posted on Asnwerhub here, https://answers.unrealengine.com/questions/220787/bug-net-cull-distance-doesnt-work-when-the-player.html Also Reproduced in Main Promotable-CL-2535351 & Rele ...

Unable to interact or collide with geometry collection after Removal on Sleep or Break timer finishes, yet unbroken piece continue to render

UE - Runtime - Simulation - Dec 18, 2025

Context: A static mesh is able to have a geometry collection generated from it using the Fracture editing mode. It can be fractured in many different ways, and when acted upon by a chaos field agent ...

Crash entering PIE without Magic Leap SDK referencing delayhlp.cpp:323

UE - Platform - XR - Jan 31, 2019

Editor crash when PIEing without ML SDK installed on machine. This did not occur at the same CL on a P4 build. This did not occur on a machine with the ML SDK installed. Does not occur in //UE4/Re ...

Ensure occurs when RBAN simulated rigid body approaches UseComplexAsSimple mesh

UE - Runtime - Simulation - Jun 30, 2022

When a collision enabled RBAN node attempts to collect surrounding meshes, if there is a mesh with UseComplexAsSimple, it will hit the Ensure when cloning a mesh on the task graph thread. Disabling ...

LIVE: EDITOR: FBX: Combined Meshes Flag does not work when importing multiple LODs in a single FBX

UE - Editor - Content Pipeline - Import and Export - Oct 10, 2014

BRANCH: MAIN CHANGELIST: 2322258 PLATFORM: Windows DESCRIPTION: When importing a mesh into the editor if there are multiple LOD setup meshes in a single FBX they will not import as a single asset w ...