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

UE - Engine Scaling - Streaming - 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 ...

Delta struct serialized fast arrays replicating new elements with no changelist

UE - Framework - 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 ...

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 ...

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 ...

Crash importing SOLIDWORKS model

UE - Editor - Content Pipeline - Datasmith - Importer - Aug 1, 2018

NetMulticast and BlueprintCallable C++ functions reportedly have incorrect parameters

UE - Networking - Nov 7, 2014

Bug report from AnswerHub. Need to figure out why C++ functions tagged NetMulticast and BlueprintCallable send the wrong paramters to some clients. ...