Unreal Engine Issues and Bug Tracker (UE-23027)

Description

If the user creates a function with local variables and then collapses the variables down into a collapsed graph and then duplicates this collapsed graph the variables in the second graph will be grayed out as though they do not exist. If the user then right clicks and uses the "Create local variable ..." option, this will crash the engine.

Steps to Reproduce

Open the Editor
Create a new Actor blueprint
Create a new function
Create a new vector local variable
Create a Set node for the new local vector
Connect it to the function
Collapse the set vector into a collapsed graph (attached image for reference)
Copy and past the collapsed graph (attached image for reference)
Open the collapsed graph
Right click the grayed out set vector and create a local variable (attached image for reference)
Notice the editor crashes

Expected: The local variable would already exist
Result: The vector does not exist after duplication and creating it causes a crash

Callstack

MachineId:E74C21034048BDD873CC6C9A3913CF6C
EpicAccountId:ccbf39de6f9245c0aa23f8e57cc8a566

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

"Assertion failed: FunctionEntryNodes.Num() [File:D:\BuildFarm\buildmachine_++depot+UE4-Releases+4.9\Engine\Source\Editor\UnrealEd\Private\Kismet2\BlueprintEditorUti

UE4Editor_Core!FDebug::AssertFailed() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\core\private\misc\outputdevice.cpp:354]
UE4Editor_UnrealEd!FBlueprintEditorUtils::AddLocalVariable() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\editor\unrealed\private\kismet2\blueprinteditorutils.cpp:4658]
UE4Editor_BlueprintGraph!UEdGraphSchema_K2::OnCreateNonExistentLocalVariable() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\editor\blueprintgraph\private\edgraphschema_k2.cpp:1543]
UE4Editor_BlueprintGraph!TBaseStaticDelegateInstance<void __cdecl(void),UK2Node_Variable * __ptr64,UBlueprint * __ptr64>::ExecuteIfSafe() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\core\public\delegates\delegateinstancesimpl_variadics.inl:921]
UE4Editor_Slate!SMenuEntryBlock::OnClicked() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slate\private\framework\multibox\smenuentryblock.cpp:988]
UE4Editor_Slate!SMenuEntryBlock::OnMenuItemButtonClicked() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slate\private\framework\multibox\smenuentryblock.cpp:939]
UE4Editor_Slate!TMemberFunctionCaller<SMenuEntryBlock,FReply (__cdecl SMenuEntryBlock::*)(void) __ptr64>::operator()<>() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\core\public\delegates\delegateinstanceinterface_variadics.h:161]
UE4Editor_Slate!TTupleImpl<TIntegerSequence<> >::ApplyAfter_ExplicitReturnType<FReply,TMemberFunctionCaller<SMenuEntryBlock,FReply (__cdecl SMenuEntryBlock::*)(void) __ptr64> >() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\core\public\delegates\tuple.h:113]
UE4Editor_Slate!TBaseSPMethodDelegateInstance<0,SMenuEntryBlock,0,FReply __cdecl(void)>::Execute() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\core\public\delegates\delegateinstancesimpl_variadics.inl:282]
UE4Editor_Slate!TBaseDelegate<FReply>::Execute() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\core\public\delegates\delegatesignatureimpl_variadics.inl:440]
UE4Editor_Slate!SButton::OnMouseButtonUp() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slate\private\widgets\input\sbutton.cpp:236]
UE4Editor_Slate!SMenuEntryButton::OnMouseButtonUp() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slate\private\framework\multibox\smenuentryblock.cpp:361]
UE4Editor_Slate!<lambda_df946b2745ea2bbab398d4acc9cc3d04>::operator()() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:4273]
UE4Editor_Slate!FEventRouter::Route<FReply,FEventRouter::FToLeafmostPolicy,FPointerEvent,<lambda_df946b2745ea2bbab398d4acc9cc3d04> >() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:214]
UE4Editor_Slate!FSlateApplication::RoutePointerUpEvent() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:4276]
UE4Editor_Slate!FSlateApplication::ProcessMouseButtonUpEvent() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:4660]
UE4Editor_Slate!FSlateApplication::OnMouseUp() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:4638]
UE4Editor_Core!FWindowsApplication::ProcessDeferredMessage() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\core\private\windows\windowsapplication.cpp:1403]
UE4Editor_Core!FWindowsApplication::DeferMessage() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\core\private\windows\windowsapplication.cpp:1708]
UE4Editor_Core!FWindowsApplication::ProcessMessage() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\core\private\windows\windowsapplication.cpp:706]
UE4Editor_Core!FWindowsApplication::AppWndProc() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\core\private\windows\windowsapplication.cpp:628]
user32
user32
UE4Editor_Core!FWindowsPlatformMisc::PumpMessages() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\core\private\windows\windowsplatformmisc.cpp:884]
UE4Editor!FEngineLoop::Tick() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\launch\private\launchengineloop.cpp:2392]
UE4Editor!GuardedMain() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\launch\private\launch.cpp:142]
UE4Editor!GuardedMainWrapper() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\launch\private\windows\launchwindows.cpp:126]
UE4Editor!WinMain() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\launch\private\windows\launchwindows.cpp:200]

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Fixed

Component	UE - Gameplay - Blueprint
Affects Versions	4.9.2
Target Fix	4.11

Fix Commit	2759056
Main Commit	2884111

Created	Nov 5, 2015
Resolved	Nov 9, 2015
Updated	Apr 27, 2018

UE-23027

Crash when creating a local variable inside of a collapsed node graph that has been copied

Crash when creating a local variable inside of a collapsed node graph that has been copied

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