Blackboard interaction crashes engine

Hi, I’m trying to implement AI and following zoombapup’s Guard AI YT tutorials. Whatever I do within Blackboard crashes the engine. Yes even a single click on Self key. Here’s the dump. I only stripped off machine and client id. Any pointers to the right direction would be appreciated.

Unknown exception - code 00000001 (first/second 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]

Dare I bump ?

Hi ,

Thank you for the report, I am investigating it,but I will need some more details. Which version of 4.7 are you using where this occurs? At what point during the tutorial does this start happening? Can you pleas attach your log file from [Project]/Saved/Logs

Once i have that information, I can look into this crash further.

Cheers!

Hi , thank you for your reply.

The crash happens when I try to replicate zoombapup’s second guard AI video, the step being Behavior Tree and Blackboard creation plus creating new key. I can create BT and BB with no problems but any click within BB crashes engine completely so I can’t create the object key needed to implement the Move To functionality.

The engine version is 4.7.6.

Please see the log attached.link text

Thanks for that information. While we look into the logs, I am going to take a look at the tutorial and try it our myself. I’ll get back to you soon with the results.

Hi ,

Though I was unable to get the crash myself, our AI developer believes he has located the problem and I have entered a report (UE-15693).

Thank you!

Thank you . Where can I look up that report ? I presume it will be updated with solutions from devs and I wouldn’t like to miss it.

I have checked on the report again and can see that it was just updated with a fix to “add a safety check to the Blackboard Editor’s key selection”. This is scheduled to be integrated into an upcoming build. Please let us know if this continues or if a new error occurs after the full release of 4.8.

Cheers!