"Pass-By-Reference" inputs to a multicast RPC can crash

UE - Networking - Oct 6, 2021

Passing a parameter by reference for an RPC does not seem to be a supported operation, and UnrealHeaderTool will already throw an error if a networked UFUNCTION includes any OutParms. However, users ...

[CrashReport] Linux crash - /usr/lib64/opengl/nvidia/lib/libGLX_nvidia.so.0

UE - Platform - Linux - Jul 20, 2017

This is a common Linux crash that has occurred since at least 4.14. ...

Crash/ensure when linking anim layers from animation update

OLD - Anim - Mar 12, 2020

Originally reported here: https://udn.unrealengine.com/questions/562047/linked-layer-animation-blueprint-proxy-missing-ske.html When linking an anim layer during update, we get either an ensure or ...

Crash if the setting of PhysicalAnimationComponent is changed in the same frame as teleport processing

UE - Simulation - Physics - Apr 24, 2020

Crash when ApplyPhysicalAnimationProfileBelow node and UPhysicalAnimationComponent :: UpdateTargetActors by UPhysicalAnimationComponent :: OnTeleport run in the same frame. Because RuntimeInstanceDa ...

Import then cancel while file is read leads to potential crash

TM - Interoperability - Oct 6, 2025

1/ Import a file with mootools such as an fbx 2/ while the file is still read, cancel the import Result : may crash few times after (when theoretically the file has finished being read) - not repr ...

Crash in FMaterialUtilities::CreateFlattenMaterialInstance when building Simplified HLOD layer

UE - World Creation - Worldbuilding Tools - HLOD - Aug 17, 2022

From licensee: The issue here starts in FVoxelizeMeshMerging::ProxyLOD() where the FlattenMaterial created using FMaterialUtilities::CreateFlattenMaterialWithSettings() returns an empty struct. I d ...

[AI] Crash when gathering heightfield geometry on worker thread

UE - AI - Navigation - Jun 25, 2025

From the body of the ticket: We aim to do as much of the work off the game thread as possible to avoid impacting frame rate. We've recently found a crash during collection of the geometry slices fr ...

Level editor viewports crash when deleting actors after a layout change

UE - Editor - Workflow Systems - Apr 18, 2022

Reported by a customer while testing USD import. See additional URL ...

[AI] Crash while loading navmesh with async static mesh compilation enabled

UE - AI - Navigation - Jun 16, 2022

I tried 10+ times but am unable to get this to reproduce locally. Licensee reports that this is a rare crash for them. ...

Opening Particle System in Debug Mode will crash Editor

UE - Graphics Features - Sep 11, 2015

Running a Project in Debug Mode and attempting to open a Particle System using a DepthFade node in Material will crash the Editor with the message listed in Callstack ...