Unreal Engine Issues and Bug Tracker (UE-49596)

Description

When a blueprint graph contains a "Make Struct" node for a blueprinted Struct, changing any pin's type causes the editor to crash when the blueprint is compiled.

Regression:
No - same behavior occurs in 4.16.3 (CL 3561208)

Steps to Reproduce

Open UE4 Editor
Create blueprint based on struct (CustomStruct)
Set MemberVar_0 to a float
Create blueprint based on actor (MyActorBP)
Add Make CutsomStruct node to event graph
Set MemberVar_0 to something other than the default value
Right click struct output pin and promote to variable
Wire variable node to begin play
Compile and save MyActorBP
In CustomStruct, change MemberVar_0 from a float to a String
Switch back to MyActorBP

Result:
Two input pins appear on the "Make struct" node. Additionlly, attempting to compile MyActorBP causes the editor to crash with provided callstack.

Expected:
Make Struct node updates to reflect the changes to the Struct. Actor blueprint using the Struct can be compiled after change are made.

Callstack

LoginId:7156c35640f86204e61b8383f45dee17
EpicAccountId:c807849e05a0413d99e379f2802cae9c

Assertion failed: BoundProperty [File:D:\Build\++UE4+Release-4.17+Compile\Sync\Engine\Source\Editor\BlueprintGraph\Private\MakeStructHandler.cpp] [Line: 115]

UE4Editor_Core!FDebug::AssertFailed() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\core\private\misc\assertionmacros.cpp:349]
UE4Editor_BlueprintGraph!FKCHandler_MakeStruct::Compile() [d:\build\++ue4+release-4.17+compile\sync\engine\source\editor\blueprintgraph\private\makestructhandler.cpp:118]
UE4Editor_KismetCompiler!FKismetCompilerContext::CompileFunction() [d:\build\++ue4+release-4.17+compile\sync\engine\source\editor\kismetcompiler\private\kismetcompiler.cpp:1894]
UE4Editor_KismetCompiler!FKismetCompilerContext::CompileFunctions() [d:\build\++ue4+release-4.17+compile\sync\engine\source\editor\kismetcompiler\private\kismetcompiler.cpp:3917]
UE4Editor_Kismet!FBlueprintCompilationManagerImpl::FlushCompilationQueueImpl() [d:\build\++ue4+release-4.17+compile\sync\engine\source\editor\kismet\private\blueprintcompilationmanager.cpp:749]
UE4Editor_Kismet!FBlueprintCompilationManagerImpl::CompileSynchronouslyImpl() [d:\build\++ue4+release-4.17+compile\sync\engine\source\editor\kismet\private\blueprintcompilationmanager.cpp:189]
UE4Editor_UnrealEd!FKismetEditorUtilities::CompileBlueprint() [d:\build\++ue4+release-4.17+compile\sync\engine\source\editor\unrealed\private\kismet2\kismet2.cpp:750]
UE4Editor_Kismet!FBlueprintEditor::Compile() [d:\build\++ue4+release-4.17+compile\sync\engine\source\editor\kismet\private\blueprinteditor.cpp:3291]
UE4Editor_Kismet!TBaseSPMethodDelegateInstance<0,FBlueprintEditor,0,TTypeWrapper<void> __cdecl(void)>::Execute() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\core\public\delegates\delegateinstancesimpl.h:327]
UE4Editor_Kismet!TBaseSPMethodDelegateInstance<0,FBlueprintEditor,0,void __cdecl(void)>::ExecuteIfSafe() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\core\public\delegates\delegateinstancesimpl.h:434]
UE4Editor_Slate!FUICommandList::ExecuteAction() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\slate\private\framework\commands\uicommandlist.cpp:97]
UE4Editor_Slate!SToolBarButtonBlock::OnClicked() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\slate\private\framework\multibox\stoolbarbuttonblock.cpp:305]
UE4Editor_Slate!TMemberFunctionCaller<SToolBarButtonBlock,FReply (__cdecl SToolBarButtonBlock::*)(void) __ptr64>::operator()<>() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\core\public\delegates\delegateinstanceinterface.h:165]
UE4Editor_Slate!UE4Tuple_Private::TTupleImpl<TIntegerSequence<unsigned int> >::ApplyAfter<TMemberFunctionCaller<SToolBarButtonBlock,FReply (__cdecl SToolBarButtonBlock::*)(void) __ptr64> >() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\core\public\templates\tuple.h:497]
UE4Editor_Slate!TBaseSPMethodDelegateInstance<0,SToolBarButtonBlock,0,FReply __cdecl(void)>::Execute() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\core\public\delegates\delegateinstancesimpl.h:327]
UE4Editor_Slate!TBaseDelegate<FReply>::Execute() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\core\public\delegates\delegatesignatureimpl.inl:537]
UE4Editor_Slate!SButton::OnMouseButtonUp() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\slate\private\widgets\input\sbutton.cpp:282]
UE4Editor_Slate!<lambda_1002768c627006711ef2f351a87ec0e7>::operator()() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:5199]
UE4Editor_Slate!FEventRouter::Route<FReply,FEventRouter::FToLeafmostPolicy,FPointerEvent,<lambda_1002768c627006711ef2f351a87ec0e7> >() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:232]
UE4Editor_Slate!FSlateApplication::RoutePointerUpEvent() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:5188]
UE4Editor_Slate!FSlateApplication::ProcessMouseButtonUpEvent() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:5690]
UE4Editor_Slate!FSlateApplication::OnMouseUp() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:5670]
UE4Editor_Core!FWindowsApplication::ProcessDeferredMessage() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\core\private\windows\windowsapplication.cpp:1718]
UE4Editor_Core!FWindowsApplication::DeferMessage() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\core\private\windows\windowsapplication.cpp:2161]
UE4Editor_Core!FWindowsApplication::ProcessMessage() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\core\private\windows\windowsapplication.cpp:881]
UE4Editor_Core!FWindowsApplication::AppWndProc() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\core\private\windows\windowsapplication.cpp:721]
user32
user32
UE4Editor_Core!FWindowsPlatformMisc::PumpMessages() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\core\private\windows\windowsplatformmisc.cpp:1009]
UE4Editor!FEngineLoop::Tick() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\launch\private\launchengineloop.cpp:3151]
UE4Editor!GuardedMain() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\launch\private\launch.cpp:166]
UE4Editor!GuardedMainWrapper() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:134]
UE4Editor!WinMain() [d:\build\++ue4+release-4.17+compile\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:210]
UE4Editor!__scrt_common_main_seh() [f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:253]
kernel32
ntdll

Community References

Unrecoverable editor crash after changing BP struct variable type

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Fixed

Component	UE - Gameplay - Blueprint
Affects Versions	4.16.3, 4.17.1, 4.17.2
Target Fix	4.17.2

Fix Commit	3637171

Created	Sep 11, 2017
Resolved	Sep 11, 2017
Updated	Apr 27, 2018

UE-49596

Editor crash on blueprint compile that contains edited BP Struct

Editor crash on blueprint compile that contains edited BP Struct

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