Crash occur when using AddSpawnableFromClass with BlueprintGeneratedClass specified

BlueprintGeneratedClass is not based UBleupint. So the following code is failed.

bool UActorFactoryBlueprint::PreSpawnActor( UObject* Asset, FTransform& InOutLocation)
{
UBlueprint* Blueprint = CastChecked<UBlueprint>(Asset);

And, the following code can fix this issue.

FSequencerBindingProxy UMovieSceneSequenceExtensions::AddSpawnableFromClass(UMovieSceneSequence* Sequence, UClass* ClassToSpawn)
{
   //FGuid NewGuid = Sequence->AllowsSpawnableObjects() ? Sequence->CreateSpawnable(ClassToSpawn) : FGuid();

   FGuid NewGuid = Sequence->AllowsSpawnableObjects() ? Sequence->CreateSpawnable(ClassToSpawn->GetDefaultObject<AActor>()) : FGuid();

return FSequencerBindingProxy(NewGuid, Sequence);
}

1. Enasble SequencerScripting plugin
2. Create LevelSeuqnece asset
3. Create Blueprint based Actor
4. Create EditorUtilityWidget
5. Add button to the new EditorUtilityWidget to run AddSpawnableFromClass with  BlueprintGeneratedClass of 3 specified 
6. Push the button to run the AddSpawnableFromClass 
7. crash

Script Stack (2 frames)[Image Removed]
ED_SequencerScripting_C.ExecuteUbergraph_ED_SequencerScripting
ED_SequencerScripting_C.BndEvt_Button_67_K2Node_ComponentBoundEvent_0_OnButtonPressedEvent_DelegateSignature

Fatal error: [Link Removed] [Line: 10] 

Cast of BlueprintGeneratedClass /Game/SequencerScripting/BP_SequencerScriptingTestCharacter.BP_SequencerScriptingTestCharacter_C to Blueprint failed

UE4Editor-Win64-Debug.exe has triggered a breakpoint.

UE4Editor_CoreUObject!CastLogError() [d:\build\release-4.22\engine\source\runtime\coreuobject\private\templates\casts.cpp:10]
UE4Editor_UnrealEd!UActorFactoryBlueprint::PreSpawnActor() [d:\build\release-4.22\engine\source\editor\unrealed\private\factories\actorfactory.cpp:1410]
UE4Editor_UnrealEd!UActorFactory::CreateActor() [d:\build\release-4.22\engine\source\editor\unrealed\private\factories\actorfactory.cpp:266]
UE4Editor_LevelSequenceEditor!FLevelSequenceEditorActorSpawner::CreateNewSpawnableType() [d:\build\release-4.22\engine\plugins\moviescene\levelsequenceeditor\source\levelsequenceeditor\private\misc\levelsequenceeditoractorspawner.cpp:95]
UE4Editor_LevelSequence!ULevelSequence::CreateSpawnable() [d:\build\release-4.22\engine\source\runtime\levelsequence\private\levelsequence.cpp:553]
UE4Editor_SequencerScripting!UMovieSceneSequenceExtensions::AddSpawnableFromClass() [d:\build\release-4.22\engine\plugins\moviescene\sequencerscripting\source\sequencerscripting\private\extensionlibraries\moviescenesequenceextensions.cpp:455]
UE4Editor_SequencerScripting!UMovieSceneSequenceExtensions::execAddSpawnableFromClass() [d:\build\release-4.22\engine\plugins\moviescene\sequencerscripting\source\sequencerscripting\public\extensionlibraries\moviescenesequenceextensions.h:22]
UE4Editor_CoreUObject!UFunction::Invoke() [d:\build\release-4.22\engine\source\runtime\coreuobject\private\uobject\class.cpp:4643]
UE4Editor_CoreUObject!UObject::CallFunction() [d:\build\release-4.22\engine\source\runtime\coreuobject\private\uobject\scriptcore.cpp:904]
UE4Editor_CoreUObject!UObject::ProcessContextOpcode() [d:\build\release-4.22\engine\source\runtime\coreuobject\private\uobject\scriptcore.cpp:2314]
UE4Editor_CoreUObject!UObject::execLet() [d:\build\release-4.22\engine\source\runtime\coreuobject\private\uobject\scriptcore.cpp:2100]
UE4Editor_CoreUObject!ProcessLocalScriptFunction() [d:\build\release-4.22\engine\source\runtime\coreuobject\private\uobject\scriptcore.cpp:974]
UE4Editor_CoreUObject!ProcessScriptFunction<void (__cdecl*)(UObject *,FFrame &,void *)>() [d:\build\release-4.22\engine\source\runtime\coreuobject\private\uobject\scriptcore.cpp:809]
UE4Editor_CoreUObject!ProcessLocalFunction() [d:\build\release-4.22\engine\source\runtime\coreuobject\private\uobject\scriptcore.cpp:1033]
UE4Editor_CoreUObject!ProcessLocalScriptFunction() [d:\build\release-4.22\engine\source\runtime\coreuobject\private\uobject\scriptcore.cpp:974]
UE4Editor_CoreUObject!UObject::ProcessInternal() [d:\build\release-4.22\engine\source\runtime\coreuobject\private\uobject\scriptcore.cpp:1058]
UE4Editor_CoreUObject!UFunction::Invoke() [d:\build\release-4.22\engine\source\runtime\coreuobject\private\uobject\class.cpp:4643]
UE4Editor_CoreUObject!UObject::ProcessEvent() [d:\build\release-4.22\engine\source\runtime\coreuobject\private\uobject\scriptcore.cpp:1464]
UE4Editor_UMG!TMulticastScriptDelegate<FWeakObjectPtr>::ProcessMulticastDelegate<UObject>() [d:\build\release-4.22\engine\source\runtime\core\public\uobject\scriptdelegates.h:488]
UE4Editor_UMG!TBaseUObjectMethodDelegateInstance<0,UButton,void __cdecl(void)>::ExecuteIfSafe() [d:\build\release-4.22\engine\source\runtime\core\public\delegates\delegateinstancesimpl.h:679]
UE4Editor_Slate!SButton::OnMouseButtonDown() [d:\build\release-4.22\engine\source\runtime\slate\private\widgets\input\sbutton.cpp:218]
UE4Editor_Slate!FEventRouter::Route<FReply,FEventRouter::FBubblePolicy,FPointerEvent,<lambda_6264868de66784e8427f79716494ab5b> >() [d:\build\release-4.22\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:271]
UE4Editor_Slate!FSlateApplication::RoutePointerDownEvent() [d:\build\release-4.22\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:5487]
UE4Editor_Slate!FSlateApplication::ProcessMouseButtonDownEvent() [d:\build\release-4.22\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:5440]
UE4Editor_Slate!FSlateApplication::OnMouseDown() [d:\build\release-4.22\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:5353]
UE4Editor_ApplicationCore!FWindowsApplication::ProcessDeferredMessage() [d:\build\release-4.22\engine\source\runtime\applicationcore\private\windows\windowsapplication.cpp:1850]
UE4Editor_ApplicationCore!FWindowsApplication::DeferMessage() [d:\build\release-4.22\engine\source\runtime\applicationcore\private\windows\windowsapplication.cpp:2292]
UE4Editor_ApplicationCore!FWindowsApplication::ProcessMessage() [d:\build\release-4.22\engine\source\runtime\applicationcore\private\windows\windowsapplication.cpp:1522]
UE4Editor_ApplicationCore!FWindowsApplication::AppWndProc() [d:\build\release-4.22\engine\source\runtime\applicationcore\private\windows\windowsapplication.cpp:772]
user32
user32
UE4Editor_ApplicationCore!FWindowsPlatformApplicationMisc::PumpMessages() [d:\build\release-4.22\engine\source\runtime\applicationcore\private\windows\windowsplatformapplicationmisc.cpp:130]
UE4Editor!FEngineLoop::Tick() [d:\build\release-4.22\engine\source\runtime\launch\private\launchengineloop.cpp:3882]
UE4Editor!GuardedMain() [d:\build\release-4.22\engine\source\runtime\launch\private\launch.cpp:168]
UE4Editor!GuardedMainWrapper() [d:\build\release-4.22\engine\source\runtime\launch\private\windows\launchwindows.cpp:145]
UE4Editor!WinMain() [d:\build\release-4.22\engine\source\runtime\launch\private\windows\launchwindows.cpp:275]
UE4Editor!__scrt_common_main_seh() [d:\agent\_work\2\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288]
kernel32
ntdll