Dragging a custom event node to event graph that is bound via output pin to an event dispatcher crashes editor

Editor crashes if a custom event function is called after a custom event has been bound to an event dispatcher. However, this only occurs if the event binding occurs from an event delegate by ref output pin on the custom event node, not from the initial output delegate.

CrashReporter [Link Removed]

Frequency: 5/5

Note: at times it requires a second compile before crash will occur.

Regression (no) issue (does) occur in 4.11.2

1. Open Editor (any project)
2. Open level blueprint
3. Create event dispatcher
4. LMB drag event dispatcher from My Blueprint pane to Event Graph>Bind
5. RMB Event Graph>Custom event
6. Drag from Event Dispatcher Bind Event pin, release LMB over custom event node under exec pin. (see image)
7. Compile
8. LMB Custom Event in My BLueprint pane, drag to event graph

Results

Editor crashes

Expected

Custom event function node created in event graph

MachineId:409D523543AE785961A2788C698A2F90
EpicAccountId:89e014249c0a480eb18ea5b683d2eb3c

Fatal error: [Link Removed] [Line: 148]
UBlueprintGeneratedClass::GetAuthoritativeClass: ClassGeneratedBy is null. class '/Engine/Transient.TRASHCLASS_66'

UE4Editor_Core!FDebug::AssertFailed() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\core\private\misc\outputdevice.cpp:440]
UE4Editor_Engine!UBlueprintGeneratedClass::GetAuthoritativeClass() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\engine\private\blueprintgeneratedclass.cpp:148]
UE4Editor_BlueprintGraph!FMemberReference::SetFromField<UFunction>() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\engine\classes\engine\memberreference.h:120]
UE4Editor_BlueprintGraph!FMemberReference::FillSimpleMemberReference<UFunction>() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\engine\classes\engine\memberreference.h:480]
UE4Editor_BlueprintGraph!UEdGraphSchema_K2::ConvertPropertyToPinType() [d:\build\++ue4+release-4.12+compile\sync\engine\source\editor\blueprintgraph\private\edgraphschema_k2.cpp:3217]
UE4Editor_BlueprintGraph!UK2Node_CallFunction::CreatePinsForFunctionCall() [d:\build\++ue4+release-4.12+compile\sync\engine\source\editor\blueprintgraph\private\k2node_callfunction.cpp:883]
UE4Editor_BlueprintGraph!UK2Node_CallFunction::AllocateDefaultPins() [d:\build\++ue4+release-4.12+compile\sync\engine\source\editor\blueprintgraph\private\k2node_callfunction.cpp:605]
UE4Editor_BlueprintGraph!UBlueprintNodeSpawner::SpawnEdGraphNode() [d:\build\++ue4+release-4.12+compile\sync\engine\source\editor\blueprintgraph\private\blueprintnodespawner.cpp:319]
UE4Editor_BlueprintGraph!UBlueprintNodeSpawner::SpawnNode<UEdGraphNode>() [d:\build\++ue4+release-4.12+compile\sync\engine\source\editor\blueprintgraph\public\blueprintnodespawner.h:294]
UE4Editor_BlueprintGraph!UBlueprintFunctionNodeSpawner::Invoke() [d:\build\++ue4+release-4.12+compile\sync\engine\source\editor\blueprintgraph\private\blueprintfunctionnodespawner.cpp:414]
UE4Editor_Kismet!FKismetFunctionDragDropAction::DroppedOnPanel() [d:\build\++ue4+release-4.12+compile\sync\engine\source\editor\kismet\private\bpfunctiondragdropaction.cpp:239]
UE4Editor_GraphEditor!SGraphPanel::OnDrop() [d:\build\++ue4+release-4.12+compile\sync\engine\source\editor\grapheditor\private\sgraphpanel.cpp:948]
UE4Editor_Slate!<lambda_d21373bc5354aa11b893894bcf47e418>::operator()() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:4630]
UE4Editor_Slate!FEventRouter::Route<FReply,FEventRouter::FBubblePolicy,FPointerEvent,<lambda_d21373bc5354aa11b893894bcf47e418> >() [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:4621]
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:1510]
UE4Editor_Core!FWindowsApplication::DeferMessage() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\core\private\windows\windowsapplication.cpp:1850]
UE4Editor_Core!FWindowsApplication::ProcessMessage() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\core\private\windows\windowsapplication.cpp:745]
UE4Editor_Core!FWindowsApplication::AppWndProc() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\core\private\windows\windowsapplication.cpp:667]
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