Blackboard interaction crashes engine

Unknown exception - code 00000001 (first/second chance not available) Assertion failed: IsValid() [File:D:\BuildFarm\buildmachine_++depot+UE4-Releases+4.7\Engine\Source\Runtime\Core\Public\Templates\SharedPointer.h] [Line: 658] KERNELBASE + 109229 bytes UE4Editor_Core!FOutputDeviceWindowsError::Serialize() + 292 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\core\private\windows\windowsplatformoutputdevices.cpp:95] UE4Editor_Core!FOutputDevice::Logf__VA() + 248 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\core\private\misc\outputdevice.cpp:144] UE4Editor_Core!FDebug::AssertFailed() + 1079 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\core\private\misc\outputdevice.cpp:224] UE4Editor_BehaviorTreeEditor!FBehaviorTreeEditor::HandleBlackboardEntrySelected() + 68 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\editor\behaviortreeeditor\private\behaviortreeeditor.cpp:343] UE4Editor_BehaviorTreeEditor!TBaseSPMethodDelegateInstance<0,FBehaviorTreeEditor,0,TTypeWrapper __cdecl(FBlackboardEntry const __ptr64,bool)>::Execute() + 89 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\core\public\delegates\delegateinstancesimpl_variadics.inl:282] UE4Editor_BehaviorTreeEditor!TBaseSPMethodDelegateInstance<0,FBehaviorTreeEditor,0,void __cdecl(FBlackboardEntry const __ptr64,bool)>::ExecuteIfSafe() + 73 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\core\public\delegates\delegateinstancesimpl_variadics.inl:388] UE4Editor_BehaviorTreeEditor!SBehaviorTreeBlackboardView::HandleActionSelected() + 522 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\editor\behaviortreeeditor\private\sbehaviortreeblackboardview.cpp:429] UE4Editor_BehaviorTreeEditor!TBaseSPMethodDelegateInstance<1,SBehaviorTreeBlackboardView,0,TTypeWrapper __cdecl(TArray,FDefaultAllocator> const & __ptr64)>::Execute() + 76 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\core\public\delegates\delegateinstancesimpl_variadics.inl:282] UE4Editor_GraphEditor!SGraphActionMenu::HandleSelection() + 153 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\editor\grapheditor\private\sgraphactionmenu.cpp:1313] UE4Editor_GraphEditor!SGraphActionMenu::OnItemSelected() + 51 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\editor\grapheditor\private\sgraphactionmenu.cpp:1138] UE4Editor_GraphEditor!TBaseSPMethodDelegateInstance<0,SGraphActionMenu,0,TTypeWrapper __cdecl(TSharedPtr,enum ESelectInfo::Type)>::Execute() + 106 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\core\public\delegates\delegateinstancesimpl_variadics.inl:282] UE4Editor_GraphEditor!TBaseSPMethodDelegateInstance<0,SGraphActionMenu,0,void __cdecl(TSharedPtr,enum ESelectInfo::Type)>::ExecuteIfSafe() + 101 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\core\public\delegates\delegateinstancesimpl_variadics.inl:388] UE4Editor_GraphEditor!TBaseDelegate,enum ESelectInfo::Type>::ExecuteIfBound() + 97 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\core\public\delegates\delegatesignatureimpl_variadics.inl:518] UE4Editor_GraphEditor!SListView >::Private_SignalSelectionChanged() + 565 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\slate\public\widgets\views\slistview.h:613] UE4Editor_GraphEditor!STableRow >::OnMouseButtonUp() + 1229 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\slate\public\widgets\views\stablerow.h:437] UE4Editor_Slate!::operator()() + 188 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:3985] UE4Editor_Slate!FEventRouter::Route >() + 215 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:202] UE4Editor_Slate!FSlateApplication::ProcessMouseButtonUpEvent() + 601 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:3988] UE4Editor_Slate!FSlateApplication::OnMouseUp() + 294 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:3949] UE4Editor_Core!FWindowsApplication::ProcessDeferredMessage() + 3573 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\core\private\windows\windowsapplication.cpp:1373] UE4Editor_Core!FWindowsApplication::DeferMessage() + 318 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\core\private\windows\windowsapplication.cpp:1669] UE4Editor_Core!FWindowsApplication::ProcessMessage() + 4016 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\core\private\windows\windowsapplication.cpp:742] UE4Editor_Core!FWindowsApplication::AppWndProc() + 114 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\core\private\windows\windowsapplication.cpp:604] user32 + 105425 bytes user32 + 104666 bytes UE4Editor_Core!FWindowsPlatformMisc::PumpMessages() + 118 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\core\private\windows\windowsplatformmisc.cpp:774] UE4Editor!FEngineLoop::Tick() + 3737 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\launch\private\launchengineloop.cpp:2233] UE4Editor!GuardedMain() + 1404 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\launch\private\launch.cpp:142] UE4Editor!GuardedMainWrapper() + 26 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\launch\private\windows\launchwindows.cpp:126] UE4Editor!WinMain() + 249 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\launch\private\windows\launchwindows.cpp:202] UE4Editor!__tmainCRTStartup() + 329 bytes [f:\dd\vctools\crt\crtw32\dllstuff\crtexe.c:618]