# Alembic Skeletal Mesh Crash on FBX Export

**URL:** <https://forums.unrealengine.com/t/alembic-skeletal-mesh-crash-on-fbx-export/371908>\
**Category:** Pipeline & Plugins\
**Tags:** export, UE4-13, unreal-engine, FBX, Alembic, question\
**Created:** [September 28, 2016, 8:47pm UTC](https://forums.unrealengine.com/t/alembic-skeletal-mesh-crash-on-fbx-export/371908 "2016-09-28T20:47:28Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![anonymous\_user\_b5aac8e1](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_b5aac8e1](https://forums.unrealengine.com/u/anonymous_user_b5aac8e1)\
**Post date:** [September 28, 2016, 8:47pm UTC](https://forums.unrealengine.com/t/alembic-skeletal-mesh-crash-on-fbx-export/371908/1 "2016-09-28T20:47:28Z")

</div>

When we try to export a FBX of a skeletal mesh generated via the Alembic importer in 4.13.

Content Browser → Right click → Asset Actions → Export

```
MachineId:C4EC4FB04ACB2A8FBF8C71B267784019
EpicAccountId:ea24650e01a54002aa8c5df8c0c44082

Assertion failed: (Index >= 0) & (Index < ArrayNum) [File:D:\Build\++UE4+Release-4.13+Compile\Sync\Engine\Source\Runtime\Core\Public\Containers\Array.h] [Line: 833] 
Array index out of bounds: 2 from an array of size 1

UE4Editor_Core!FDebug::AssertFailed() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\private\misc\outputdevice.cpp:421]
UE4Editor_UnrealEd!UnFbx::FFbxExporter::BindMeshToSkeleton() [d:\build\++ue4+release-4.13+compile\sync\engine\source\editor\unrealed\private\fbx\fbxskeletalmeshexport.cpp:319]
UE4Editor_UnrealEd!UnFbx::FFbxExporter::ExportSkeletalMeshToFbx() [d:\build\++ue4+release-4.13+compile\sync\engine\source\editor\unrealed\private\fbx\fbxskeletalmeshexport.cpp:494]
UE4Editor_UnrealEd!UnFbx::FFbxExporter::ExportSkeletalMesh() [d:\build\++ue4+release-4.13+compile\sync\engine\source\editor\unrealed\private\fbx\fbxmainexport.cpp:912]
UE4Editor_UnrealEd!USkeletalMeshExporterFBX::ExportBinary() [d:\build\++ue4+release-4.13+compile\sync\engine\source\editor\unrealed\private\editorexporters.cpp:1811]
UE4Editor_Engine!UExporter::ExportToArchive() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\engine\private\unrealexporter.cpp:110]
UE4Editor_Engine!UExporter::ExportToFileEx() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\engine\private\unrealexporter.cpp:414]
UE4Editor_UnrealEd!ObjectTools::ExportObjects() [d:\build\++ue4+release-4.13+compile\sync\engine\source\editor\unrealed\private\objecttools.cpp:3411]
UE4Editor_ContentBrowser!FAssetContextMenu::ExecuteExport() [d:\build\++ue4+release-4.13+compile\sync\engine\source\editor\contentbrowser\private\assetcontextmenu.cpp:1943]
UE4Editor_ContentBrowser!TBaseSPMethodDelegateInstance<0,FAssetContextMenu,0,TTypeWrapper<void> __cdecl(void)>::Execute() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\public\delegates\delegateinstancesimpl.h:317]
UE4Editor_ContentBrowser!TBaseSPMethodDelegateInstance<0,FAssetContextMenu,0,void __cdecl(void)>::ExecuteIfSafe() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\public\delegates\delegateinstancesimpl.h:423]
UE4Editor_Slate!SMenuEntryBlock::OnClicked() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\slate\private\framework\multibox\smenuentryblock.cpp:1036]
UE4Editor_Slate!SMenuEntryBlock::OnMenuItemButtonClicked() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\slate\private\framework\multibox\smenuentryblock.cpp:987]
UE4Editor_Slate!TMemberFunctionCaller<SMenuEntryBlock,FReply (__cdecl SMenuEntryBlock::*)(void)__ptr64>::operator()<>() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\public\delegates\delegateinstanceinterface.h:161]
UE4Editor_Slate!TTupleImpl<TIntegerSequence<unsigned int> >::ApplyAfter<TMemberFunctionCaller<SMenuEntryBlock,FReply (__cdecl SMenuEntryBlock::*)(void)__ptr64> >() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\public\delegates\tuple.h:115]
UE4Editor_Slate!TBaseSPMethodDelegateInstance<0,SMenuEntryBlock,0,FReply __cdecl(void)>::Execute() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\public\delegates\delegateinstancesimpl.h:317]
UE4Editor_Slate!TBaseDelegate<FReply>::Execute() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\public\delegates\delegatesignatureimpl.inl:521]
UE4Editor_Slate!SButton::OnMouseButtonUp() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\slate\private\widgets\input\sbutton.cpp:278]
UE4Editor_Slate!SMenuEntryButton::OnMouseButtonUp() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\slate\private\framework\multibox\smenuentryblock.cpp:385]
UE4Editor_Slate!<lambda_8d0e9a1da76abd0a756a3a9d775f5ed1>::operator()() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:4901]
UE4Editor_Slate!FEventRouter::Route<FReply,FEventRouter::FToLeafmostPolicy,FPointerEvent,<lambda_8d0e9a1da76abd0a756a3a9d775f5ed1> >() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:215]
UE4Editor_Slate!FSlateApplication::RoutePointerUpEvent() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:4890]
UE4Editor_Slate!FSlateApplication::ProcessMouseButtonUpEvent() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:5348]
UE4Editor_Slate!FSlateApplication::OnMouseUp() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:5328]
UE4Editor_Core!FWindowsApplication::ProcessDeferredMessage() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\private\windows\windowsapplication.cpp:1584]
UE4Editor_Core!FWindowsApplication::DeferMessage() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\private\windows\windowsapplication.cpp:1930]
UE4Editor_Core!FWindowsApplication::ProcessMessage() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\private\windows\windowsapplication.cpp:747]
UE4Editor_Core!FWindowsApplication::AppWndProc() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\private\windows\windowsapplication.cpp:669]
user32
user32
UE4Editor_Core!FWindowsPlatformMisc::PumpMessages() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\private\windows\windowsplatformmisc.cpp:905]
UE4Editor!FEngineLoop::Tick() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\launch\private\launchengineloop.cpp:2788]
UE4Editor!GuardedMain() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\launch\private\launch.cpp:156]
UE4Editor!GuardedMainWrapper() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:126]
UE4Editor!WinMain() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:202]
UE4Editor!__scrt_common_main_seh() [f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:264]
kernel32
ntdll

```

---

<div class="post-metadata">

**Author:** ![Tim\_Hobson](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Tim\_Hobson](https://forums.unrealengine.com/u/Tim_Hobson)\
**Post date:** [September 29, 2016, 3:07pm UTC](https://forums.unrealengine.com/t/alembic-skeletal-mesh-crash-on-fbx-export/371908/2 "2016-09-29T15:07:59Z")

</div>

Hi BLVD-MTL,

I’ve submitted a ticket for this to be investigated. You can follow the status here: [Unreal Engine Issues and Bug Tracker (UE-36602)](https://issues.unrealengine.com/issue/UE-36602)

Thank you!

Tim

---

<div class="post-metadata">

**Author:** ![anonymous\_user\_b5aac8e1](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_b5aac8e1](https://forums.unrealengine.com/u/anonymous_user_b5aac8e1)\
**Post date:** [October 3, 2016, 3:03pm UTC](https://forums.unrealengine.com/t/alembic-skeletal-mesh-crash-on-fbx-export/371908/3 "2016-10-03T15:03:59Z")

</div>

Hey Tim,

Thanks you very much for your time, have i noticed the ticked is currently fixed. How can i access to the Fix Commit: 3145222? To patch it on my side?

Thanks for your time,

---

<div class="post-metadata">

**Author:** ![Tim\_Hobson](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Tim\_Hobson](https://forums.unrealengine.com/u/Tim_Hobson)\
**Post date:** [October 3, 2016, 3:15pm UTC](https://forums.unrealengine.com/t/alembic-skeletal-mesh-crash-on-fbx-export/371908/4 "2016-10-03T15:15:38Z")

</div>

The fix has been implemented in one of our lower streams (Dev-Framework), but has not necessarily been merged back to Main yet. Once the chunk of fixes has been merged to Main you’ll have access to it via GitHub’s Master branch, but I won’t know the specific merge you’ll need to look at, though, since it’ll have multiple CLs and at least should break them up in some readable fashion. I’m just not sure. I don’t mess with GitHub very often.