Deleting the code files for a custom component from a project will result in an Engine crash when trying to open any Blueprint using that component.

Adding a custom component to a Blueprint and then deleting the code class defining that custom component from the project will crash the Editor any time you try to open a Blueprint containing that custom component.

1. Create a new code project using the First Person template.
2. Add a new code class to the project derived from SceneComponent.
3. Close the Editor.
4. Build the project in Visual Studio.
5. Open the project in the Editor.
6. Create a new Actor Blueprint.
7. Add the component created in step 2 to the new Blueprint.
8. Compile and save the Blueprint.
9. Close the Editor and Visual Studio.
10. Delete the header and source files for the component created in step 2 from the project.
11. Regenerate project files.
12. Build the project in Visual Studio.
13. Open the project in the Editor.
14. Attempt to open the Blueprint created in step 6.

RESULT:
The Editor crashes.

EXPECTED:
The Blueprint opens and displays an error/warning that the custom component can no longer be used.

MachineId:926CC4CD4DE75FA30341E2895D619D6E

Unknown exception - code 00000001 (first/second chance not available)

Assertion failed: InSCSNode->ComponentTemplate != NULL [Link Removed] [Line: 4947]

KERNELBASE + 37901 bytes
UE4Editor_Core!FOutputDeviceWindowsError::Serialize() + 292 bytes [d:\main-builds\ue4\engine\source\runtime\core\private\windows\windowsplatformoutputdevices.cpp:95]
UE4Editor_Core!FOutputDevice::Logf__VA() + 248 bytes [d:\main-builds\ue4\engine\source\runtime\core\private\misc\outputdevice.cpp:144]
UE4Editor_Core!FDebug::AssertFailed() + 1079 bytes [d:\main-builds\ue4\engine\source\runtime\core\private\misc\outputdevice.cpp:224]
UE4Editor_Kismet!SSCSEditor::AddTreeNode() + 180 bytes [d:\main-builds\ue4\engine\source\editor\kismet\private\sscseditor.cpp:4957]
UE4Editor_Kismet!SSCSEditor::UpdateTree() + 2849 bytes [d:\main-builds\ue4\engine\source\editor\kismet\private\sscseditor.cpp:4091]
UE4Editor_Kismet!SSCSEditor::Construct() + 13679 bytes [d:\main-builds\ue4\engine\source\editor\kismet\private\sscseditor.cpp:3245]
UE4Editor_Kismet!TDecl<SSCSEditor,RequiredArgs::T0RequiredArgs>::operator<<=() + 138 bytes [d:\main-builds\ue4\engine\source\runtime\slatecore\public\widgets\declarativesyntaxsupport.h:1343]
UE4Editor_Kismet!FBlueprintEditor::CreateSCSEditors() + 760 bytes [d:\main-builds\ue4\engine\source\editor\kismet\private\blueprinteditor.cpp:2126]
UE4Editor_Kismet!FBlueprintEditor::CreateDefaultTabContents() + 4028 bytes [d:\main-builds\ue4\engine\source\editor\kismet\private\blueprinteditor.cpp:2115]
UE4Editor_Kismet!FBlueprintEditor::CommonInitialization() + 1410 bytes [d:\main-builds\ue4\engine\source\editor\kismet\private\blueprinteditor.cpp:1415]
UE4Editor_Kismet!FBlueprintEditor::InitBlueprintEditor() + 1305 bytes [d:\main-builds\ue4\engine\source\editor\kismet\private\blueprinteditor.cpp:1538]
UE4Editor_Kismet!FBlueprintEditorModule::CreateBlueprintEditor() + 454 bytes [d:\main-builds\ue4\engine\source\editor\kismet\private\blueprinteditormodule.cpp:152]
UE4Editor_AssetTools!FAssetTypeActions_Blueprint::OpenAssetEditor() + 380 bytes [d:\main-builds\ue4\engine\source\developer\assettools\private\assettypeactions\assettypeactions_blueprint.cpp:77]
UE4Editor_UnrealEd!FAssetEditorManager::OpenEditorForAsset() + 1085 bytes [d:\main-builds\ue4\engine\source\editor\unrealed\private\toolkits\asseteditormanager.cpp:301]
UE4Editor_AssetTools!FAssetTypeActions_Base::AssetsActivated() + 156 bytes [d:\main-builds\ue4\engine\source\developer\assettools\public\assettypeactions_base.h:37]
UE4Editor_ContentBrowser!SContentBrowser::OnAssetsActivated() + 2580 bytes [d:\main-builds\ue4\engine\source\editor\contentbrowser\private\scontentbrowser.cpp:1546]
UE4Editor_ContentBrowser!TBaseSPMethodDelegateInstance<0,SContentBrowser,0,TTypeWrapper<void> __cdecl(TArray<FAssetData,FDefaultAllocator> const & __ptr64,enum EAssetTypeActivationMethod::Type)>::Execute() + 87 bytes [d:\main-builds\ue4\engine\source\runtime\core\public\delegates\delegateinstancesimpl_variadics.inl:282]
UE4Editor_ContentBrowser!TBaseSPMethodDelegateInstance<0,SContentBrowser,0,void __cdecl(TArray<FAssetData,FDefaultAllocator> const & __ptr64,enum EAssetTypeActivationMethod::Type)>::ExecuteIfSafe() + 71 bytes [d:\main-builds\ue4\engine\source\runtime\core\public\delegates\delegateinstancesimpl_variadics.inl:388]
UE4Editor_ContentBrowser!SAssetView::OnListMouseButtonDoubleClick() + 835 bytes [d:\main-builds\ue4\engine\source\editor\contentbrowser\private\sassetview.cpp:3203]
UE4Editor_ContentBrowser!TBaseSPMethodDelegateInstance<0,SAssetView,0,TTypeWrapper<void> __cdecl(TSharedPtr<FAssetViewItem,0>)>::Execute() + 97 bytes [d:\main-builds\ue4\engine\source\runtime\core\public\delegates\delegateinstancesimpl_variadics.inl:282]
UE4Editor_ContentBrowser!TBaseSPMethodDelegateInstance<0,SAssetView,0,void __cdecl(TSharedPtr<FAssetViewItem,0>)>::ExecuteIfSafe() + 90 bytes [d:\main-builds\ue4\engine\source\runtime\core\public\delegates\delegateinstancesimpl_variadics.inl:388]
UE4Editor_ContentBrowser!TBaseDelegate<void,TSharedPtr<FAssetViewItem,0> >::ExecuteIfBound() + 86 bytes [d:\main-builds\ue4\engine\source\runtime\core\public\delegates\delegatesignatureimpl_variadics.inl:519]
UE4Editor_ContentBrowser!SListView<TSharedPtr<FAssetViewItem,0> >::Private_OnItemDoubleClicked() + 63 bytes [d:\main-builds\ue4\engine\source\runtime\slate\public\widgets\views\slistview.h:697]
UE4Editor_ContentBrowser!STableRow<TSharedPtr<FAssetViewItem,0> >::OnMouseButtonDoubleClick() + 223 bytes [d:\main-builds\ue4\engine\source\runtime\slate\public\widgets\views\stablerow.h:252]
UE4Editor_Slate!<lambda_58ede244782f1e594383d45514e1d7c8>::operator()() + 30 bytes [d:\main-builds\ue4\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:4047]
UE4Editor_Slate!FEventRouter::Route<FReply,FEventRouter::FBubblePolicy,FPointerEvent,<lambda_58ede244782f1e594383d45514e1d7c8> >() + 189 bytes [d:\main-builds\ue4\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:210]
UE4Editor_Slate!FSlateApplication::ProcessMouseButtonDoubleClickEvent() + 499 bytes [d:\main-builds\ue4\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:4048]
UE4Editor_Slate!FSlateApplication::OnMouseDoubleClick() + 315 bytes [d:\main-builds\ue4\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:4028]
UE4Editor_Core!FWindowsApplication::ProcessDeferredMessage() + 3220 bytes [d:\main-builds\ue4\engine\source\runtime\core\private\windows\windowsapplication.cpp:1348]
UE4Editor_Core!FWindowsApplication::DeferMessage() + 318 bytes [d:\main-builds\ue4\engine\source\runtime\core\private\windows\windowsapplication.cpp:1710]
UE4Editor_Core!FWindowsApplication::ProcessMessage() + 4359 bytes [d:\main-builds\ue4\engine\source\runtime\core\private\windows\windowsapplication.cpp:711]
UE4Editor_Core!FWindowsApplication::AppWndProc() + 114 bytes [d:\main-builds\ue4\engine\source\runtime\core\private\windows\windowsapplication.cpp:629]
user32 + 105425 bytes
user32 + 104666 bytes
UE4Editor_Core!FWindowsPlatformMisc::PumpMessages() + 118 bytes [d:\main-builds\ue4\engine\source\runtime\core\private\windows\windowsplatformmisc.cpp:775]
UE4Editor!FEngineLoop::Tick() + 3737 bytes [d:\main-builds\ue4\engine\source\runtime\launch\private\launchengineloop.cpp:2239]
UE4Editor!GuardedMain() + 1404 bytes [d:\main-builds\ue4\engine\source\runtime\launch\private\launch.cpp:142]
UE4Editor!GuardedMainWrapper() + 26 bytes [d:\main-builds\ue4\engine\source\runtime\launch\private\windows\launchwindows.cpp:126]
UE4Editor!WinMain() + 249 bytes [d:\main-builds\ue4\engine\source\runtime\launch\private\windows\launchwindows.cpp:202]
UE4Editor!__tmainCRTStartup() + 329 bytes [f:\dd\vctools\crt\crtw32\dllstuff\crtexe.c:618]

Crash / corrupt blueprint