Crash when importing material assigned to FBX with illegal characters through the Full Scene Importer

If you have an illegal character (/ or ?) in your material name embedded with your FBX the editor will crash when using the new Full scene importer and selecting the Materials Tab.

Tested in and crashes in both:
4.12.3 CL-3013449
4.13 Dev-Editor CL-3018237

1. Create or use the file attached with a material that has a name with an illegal character. I used "/" for mine.
2.Open UE4
3. Go to File > Import into Scene
4. Select the FBX with the material assignment
5. Click the Materials tab in the Full Scene Importer window

Regression: No

Results: Editor will crash

Expected: Editor should not crash and should likely throw an error message or replace illegal characters with an underscore ( _ ).

Fatal error: [Link Removed] [Line: 530]
Attempted to create a package with name containing double slashes. PackageName: /Game//Bark_Mat

UE4Editor_Core!FDebug::AssertFailed() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\core\private\misc\outputdevice.cpp:440]
UE4Editor_CoreUObject!CreatePackage() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:533]
UE4Editor_CoreUObject!ResolveName() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:700]
UE4Editor_CoreUObject!StaticLoadObjectInternal() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:783]
UE4Editor_CoreUObject!StaticLoadObject() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:853]
UE4Editor_CoreUObject!StaticFindObject() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:231]
UE4Editor_CoreUObject!StaticFindObjectSafe() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:275]
UE4Editor_UnrealEd!FFbxAttributeInfo::GetContentObject() [d:\build\++ue4+release-4.12+compile\sync\engine\source\editor\unrealed\private\fbx\fbxsceneimportfactory.cpp:651]
UE4Editor_UnrealEd!SFbxMaterialItemTableListViewRow::GetAssetStatus() [d:\build\++ue4+release-4.12+compile\sync\engine\source\editor\unrealed\private\fbx\sscenematerialslistview.cpp:116]
UE4Editor_UnrealEd!TMemberFunctionCaller<SFbxMaterialItemTableListViewRow,FText (__cdecl SFbxMaterialItemTableListViewRow::*)(void)const __ptr64>::operator()<>() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\core\public\delegates\delegateinstanceinterface_variadics.h:161]
UE4Editor_UnrealEd!TTupleImpl<TIntegerSequence<unsigned int> >::ApplyAfter_ExplicitReturnType<FText,TMemberFunctionCaller<SFbxMaterialItemTableListViewRow,FText (__cdecl SFbxMaterialItemTableListViewRow::*)(void)const __ptr64> >() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\core\public\delegates\tuple.h:128]
UE4Editor_UnrealEd!TBaseSPMethodDelegateInstance<1,SFbxMaterialItemTableListViewRow,0,FText __cdecl(void)>::Execute() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\core\public\delegates\delegateinstancesimpl_variadics.inl:321]
UE4Editor_Slate!TBaseDelegate<FText>::Execute() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\core\public\delegates\delegatesignatureimpl_variadics.inl:521]
UE4Editor_Slate!TAttribute<FText>::Get() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\core\public\misc\attribute.h:135]
UE4Editor_Slate!FTextBlockLayout::ComputeDesiredSize() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slate\private\widgets\text\textblocklayout.cpp:50]
UE4Editor_Slate!STextBlock::ComputeDesiredSize() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slate\private\widgets\text\stextblock.cpp:176]
UE4Editor_SlateCore!SWidget::CacheDesiredSize() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\swidget.cpp:388]
UE4Editor_SlateCore!SWidget::SlatePrepass() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\swidget.cpp:376]
UE4Editor_SlateCore!SWidget::SlatePrepass() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\swidget.cpp:376]
UE4Editor_UnrealEd!SListView<TSharedPtr<FFbxMaterialInfo,0> >::GenerateWidgetForItem() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slate\public\widgets\views\slistview.h:909]
UE4Editor_UnrealEd!SListView<TSharedPtr<FFbxMaterialInfo,0> >::ReGenerateItems() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slate\public\widgets\views\slistview.h:804]
UE4Editor_Slate!STableViewBase::Tick() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slate\private\widgets\views\stableviewbase.cpp:237]
UE4Editor_SlateCore!SWidget::Paint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\swidget.cpp:657]
UE4Editor_SlateCore!SPanel::PaintArrangedChildren() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\spanel.cpp:44]
UE4Editor_SlateCore!SPanel::OnPaint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\spanel.cpp:19]
UE4Editor_SlateCore!SWidget::Paint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\swidget.cpp:660]
UE4Editor_SlateCore!SPanel::PaintArrangedChildren() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\spanel.cpp:44]
UE4Editor_SlateCore!SPanel::OnPaint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\spanel.cpp:19]
UE4Editor_SlateCore!SWidget::Paint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\swidget.cpp:660]
UE4Editor_SlateCore!SPanel::PaintArrangedChildren() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\spanel.cpp:44]
UE4Editor_SlateCore!SPanel::OnPaint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\spanel.cpp:19]
UE4Editor_SlateCore!SWidget::Paint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\swidget.cpp:660]
UE4Editor_SlateCore!SCompoundWidget::OnPaint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\scompoundwidget.cpp:25]
UE4Editor_Slate!SBorder::OnPaint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slate\private\widgets\layout\sborder.cpp:90]
UE4Editor_SlateCore!SWidget::Paint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\swidget.cpp:660]
UE4Editor_SlateCore!SOverlay::OnPaint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\soverlay.cpp:100]
UE4Editor_SlateCore!SWidget::Paint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\swidget.cpp:660]
UE4Editor_SlateCore!SPanel::PaintArrangedChildren() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\spanel.cpp:44]
UE4Editor_SlateCore!SPanel::OnPaint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\spanel.cpp:19]
UE4Editor_SlateCore!SWidget::Paint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\swidget.cpp:660]
UE4Editor_SlateCore!SCompoundWidget::OnPaint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\scompoundwidget.cpp:25]
UE4Editor_SlateCore!SWidget::Paint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\swidget.cpp:660]
UE4Editor_SlateCore!SPanel::PaintArrangedChildren() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\spanel.cpp:44]
UE4Editor_Slate!SSplitter::OnPaint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slate\private\widgets\layout\ssplitter.cpp:166]
UE4Editor_SlateCore!SWidget::Paint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\swidget.cpp:660]
UE4Editor_SlateCore!SOverlay::OnPaint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\soverlay.cpp:100]
UE4Editor_SlateCore!SWidget::Paint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\swidget.cpp:660]
UE4Editor_SlateCore!SCompoundWidget::OnPaint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\scompoundwidget.cpp:25]
UE4Editor_SlateCore!SWidget::Paint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\swidget.cpp:660]
UE4Editor_SlateCore!SPanel::PaintArrangedChildren() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\spanel.cpp:44]
UE4Editor_SlateCore!SPanel::OnPaint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\spanel.cpp:19]
UE4Editor_SlateCore!SWidget::Paint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\swidget.cpp:660]
UE4Editor_SlateCore!SCompoundWidget::OnPaint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\scompoundwidget.cpp:25]
UE4Editor_Slate!SBorder::OnPaint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slate\private\widgets\layout\sborder.cpp:90]
UE4Editor_SlateCore!SWidget::Paint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\swidget.cpp:660]
UE4Editor_SlateCore!SCompoundWidget::OnPaint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\scompoundwidget.cpp:25]
UE4Editor_SlateCore!SWidget::Paint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\swidget.cpp:660]
UE4Editor_SlateCore!SPanel::PaintArrangedChildren() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\spanel.cpp:44]
UE4Editor_SlateCore!SPanel::OnPaint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\spanel.cpp:19]
UE4Editor_SlateCore!SWidget::Paint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\swidget.cpp:660]
UE4Editor_SlateCore!SPanel::PaintArrangedChildren() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\spanel.cpp:44]
UE4Editor_SlateCore!SPanel::OnPaint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\spanel.cpp:19]
UE4Editor_SlateCore!SWidget::Paint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\swidget.cpp:660]
UE4Editor_SlateCore!SOverlay::OnPaint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\soverlay.cpp:100]
UE4Editor_SlateCore!SWidget::Paint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\swidget.cpp:660]
UE4Editor_SlateCore!SCompoundWidget::OnPaint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\scompoundwidget.cpp:25]
UE4Editor_SlateCore!SWindow::OnPaint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\swindow.cpp:1761]
UE4Editor_SlateCore!SWidget::Paint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slatecore\private\widgets\swidget.cpp:660]
UE4Editor_Slate!FSlateApplication::DrawWindowAndChildren() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:1008]
UE4Editor_Slate!FSlateApplication::PrivateDrawWindows() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:1207]
UE4Editor_Slate!FSlateApplication::DrawWindows() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:969]
UE4Editor_Slate!FSlateApplication::TickApplication() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:1558]
UE4Editor_Slate!FSlateApplication::AddModalWindow() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:1874]
UE4Editor_UnrealEd!GetFbxSceneImportOptions() [d:\build\++ue4+release-4.12+compile\sync\engine\source\editor\unrealed\private\fbx\fbxsceneimportfactory.cpp:129]
UE4Editor_UnrealEd!UFbxSceneImportFactory::FactoryCreateBinary() [d:\build\++ue4+release-4.12+compile\sync\engine\source\editor\unrealed\private\fbx\fbxsceneimportfactory.cpp:855]
UE4Editor_UnrealEd!UFbxSceneImportFactory::FactoryCreateBinary() [d:\build\++ue4+release-4.12+compile\sync\engine\source\editor\unrealed\private\fbx\fbxsceneimportfactory.cpp:765]
UE4Editor_UnrealEd!UFactory::FactoryCreateFile() [d:\build\++ue4+release-4.12+compile\sync\engine\source\editor\unrealed\private\factories\factory.cpp:72]
UE4Editor_UnrealEd!UFactory::ImportObject() [d:\build\++ue4+release-4.12+compile\sync\engine\source\editor\unrealed\private\factories\factory.cpp:143]
UE4Editor_AssetTools!FAssetTools::ImportAssets() [d:\build\++ue4+release-4.12+compile\sync\engine\source\developer\assettools\private\assettools.cpp:965]
UE4Editor_UnrealEd!FEditorFileUtils::Import() [d:\build\++ue4+release-4.12+compile\sync\engine\source\editor\unrealed\private\filehelpers.cpp:1039]
UE4Editor_UnrealEd!FEditorFileUtils::Import() [d:\build\++ue4+release-4.12+compile\sync\engine\source\editor\unrealed\private\filehelpers.cpp:1002]
UE4Editor_LevelEditor!TBaseStaticDelegateInstance<void __cdecl(void)>::ExecuteIfSafe() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\core\public\delegates\delegateinstancesimpl_variadics.inl:1021]
UE4Editor_Slate!FUICommandList::ExecuteAction() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slate\private\framework\commands\uicommandlist.cpp:87]
UE4Editor_Slate!SMenuEntryBlock::OnClicked() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slate\private\framework\multibox\smenuentryblock.cpp:1027]
UE4Editor_Slate!SMenuEntryBlock::OnMenuItemButtonClicked() [d:\build\++ue4+release-4.12+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-4.12+compile\sync\engine\source\runtime\core\public\delegates\delegateinstanceinterface_variadics.h:161]
UE4Editor_Slate!TTupleImpl<TIntegerSequence<unsigned int> >::ApplyAfter_ExplicitReturnType<FReply,TMemberFunctionCaller<SMenuEntryBlock,FReply (__cdecl SMenuEntryBlock::*)(void) __ptr64> >() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\core\public\delegates\tuple.h:128]
UE4Editor_Slate!TBaseSPMethodDelegateInstance<0,SMenuEntryBlock,0,FReply __cdecl(void)>::Execute() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\core\public\delegates\delegateinstancesimpl_variadics.inl:321]
UE4Editor_Slate!TBaseDelegate<FReply>::Execute() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\core\public\delegates\delegatesignatureimpl_variadics.inl:521]
UE4Editor_Slate!SButton::OnMouseButtonUp() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slate\private\widgets\input\sbutton.cpp:275]
UE4Editor_Slate!SMenuEntryButton::OnMouseButtonUp() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slate\private\framework\multibox\smenuentryblock.cpp:385]
UE4Editor_Slate!<lambda_8d0e9a1da76abd0a756a3a9d775f5ed1>::operator()() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:4598]
UE4Editor_Slate!FEventRouter::Route<FReply,FEventRouter::FToLeafmostPolicy,FPointerEvent,<lambda_8d0e9a1da76abd0a756a3a9d775f5ed1> >() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:215]
UE4Editor_Slate!FSlateApplication::RoutePointerUpEvent() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:4587]
UE4Editor_Slate!FSlateApplication::ProcessMouseButtonUpEvent() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:5041]
UE4Editor_Slate!FSlateApplication::OnMouseUp() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:5021]
UE4Editor_Core!FWindowsApplication::ProcessDeferredMessage() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\core\private\windows\windowsapplication.cpp:1507]
UE4Editor_Core!FWindowsApplication::DeferMessage() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\core\private\windows\windowsapplication.cpp:1847]
UE4Editor_Core!FWindowsApplication::ProcessMessage() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\core\private\windows\windowsapplication.cpp:742]
UE4Editor_Core!FWindowsApplication::AppWndProc() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\core\private\windows\windowsapplication.cpp:664]
user32
user32
UE4Editor_Core!FWindowsPlatformMisc::PumpMessages() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\core\private\windows\windowsplatformmisc.cpp:903]
UE4Editor!FEngineLoop::Tick() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\launch\private\launchengineloop.cpp:2729]
UE4Editor!GuardedMain() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\launch\private\launch.cpp:148]
UE4Editor!GuardedMainWrapper() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:126]
UE4Editor!WinMain() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:200]
UE4Editor!__scrt_common_main_seh() [f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:264]
kernel32
ntdll