Crash right-clicking in anim blueprint asset picker

Editor crashes when right-clicking in the blank area of the anim blueprint asset picker

1. Open Third Person Blueprint Template in UE4.15
2. Open an anim blueprint
3. In the upper right, click on the down arrow to reveal the asset shortcut drop down menu.
4. Right-click in the blank area below the list of assets*
   Result: Crash occurs
   Expected: No crash, the editor to perform as expected
   *Note: This refers to the blank area in the drop down asset menu after the end of the list. If the list is too long, a blank area will not exist, but clicking after the last item, in this case, will sometimes trigger the crash.

Assertion failed: Asset [Link Removed] [Line: 281]

UE4Editor_Core!FDebug::AssertFailed() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\core\private\misc\assertionmacros.cpp:349]
UE4Editor_UnrealEd!FAssetEditorManager::OpenEditorForAsset() [d:\build\++ue4+release-4.15+compile\sync\engine\source\editor\unrealed\private\toolkits\asseteditormanager.cpp:281]
UE4Editor_UnrealEd!FAssetEditorManager::OpenEditorForAssets() [d:\build\++ue4+release-4.15+compile\sync\engine\source\editor\unrealed\private\toolkits\asseteditormanager.cpp:374]
UE4Editor_Persona!SAssetShortcut::HandleAssetSelectedFromPicker() [d:\build\++ue4+release-4.15+compile\sync\engine\source\editor\persona\private\sassetfamilyshortcutbar.cpp:280]
UE4Editor_Persona!TBaseSPMethodDelegateInstance<0,SAssetShortcut,0,TTypeWrapper<void> __cdecl(FAssetData const & __ptr64)>::Execute() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\core\public\delegates\delegateinstancesimpl.h:327]
UE4Editor_Persona!TBaseSPMethodDelegateInstance<0,SAssetShortcut,0,void __cdecl(FAssetData const & __ptr64)>::ExecuteIfSafe() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\core\public\delegates\delegateinstancesimpl.h:434]
UE4Editor_ContentBrowser!SAssetView::AssetSelectionChanged() [d:\build\++ue4+release-4.15+compile\sync\engine\source\editor\contentbrowser\private\sassetview.cpp:3562]
UE4Editor_ContentBrowser!TBaseSPMethodDelegateInstance<0,SAssetView,0,TTypeWrapper<void> __cdecl(TSharedPtr<FAssetViewItem,0>,enum ESelectInfo::Type)>::Execute() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\core\public\delegates\delegateinstancesimpl.h:327]
UE4Editor_ContentBrowser!TBaseSPMethodDelegateInstance<0,SAssetView,0,void __cdecl(TSharedPtr<FAssetViewItem,0>,enum ESelectInfo::Type)>::ExecuteIfSafe() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\core\public\delegates\delegateinstancesimpl.h:434]
UE4Editor_ContentBrowser!TBaseDelegate<void,TSharedPtr<FAssetViewItem,0>,enum ESelectInfo::Type>::ExecuteIfBound() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\core\public\delegates\delegatesignatureimpl.inl:624]
UE4Editor_ContentBrowser!SListView<TSharedPtr<FAssetViewItem,0> >::Private_SignalSelectionChanged() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\slate\public\widgets\views\slistview.h:720]
UE4Editor_ContentBrowser!SListView<TSharedPtr<FAssetViewItem,0> >::OnMouseButtonUp() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\slate\public\widgets\views\slistview.h:430]
UE4Editor_Slate!<lambda_6fe3fac4210ea4fdbbd9f162046616f6>::operator()() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:5111]
UE4Editor_Slate!FEventRouter::Route<FReply,FEventRouter::FBubblePolicy,FPointerEvent,<lambda_6fe3fac4210ea4fdbbd9f162046616f6> >() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:238]
UE4Editor_Slate!FSlateApplication::RoutePointerUpEvent() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:5098]
UE4Editor_Slate!FSlateApplication::ProcessMouseButtonUpEvent() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:5531]
UE4Editor_Slate!FSlateApplication::OnMouseUp() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:5508]
UE4Editor_Core!FWindowsApplication::ProcessDeferredMessage() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\core\private\windows\windowsapplication.cpp:1698]
UE4Editor_Core!FWindowsApplication::DeferMessage() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\core\private\windows\windowsapplication.cpp:2120]
UE4Editor_Core!FWindowsApplication::ProcessMessage() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\core\private\windows\windowsapplication.cpp:867]
UE4Editor_Core!FWindowsApplication::AppWndProc() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\core\private\windows\windowsapplication.cpp:714]
user32
user32
UE4Editor_Core!FWindowsPlatformMisc::PumpMessages() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\core\private\windows\windowsplatformmisc.cpp:980]
UE4Editor!FEngineLoop::Tick() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\launch\private\launchengineloop.cpp:2977]
UE4Editor!GuardedMain() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\launch\private\launch.cpp:166]
UE4Editor!GuardedMainWrapper() [d:\build\++ue4+release-4.15+compile\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:134]
UE4Editor!WinMain() [d:\build\++ue4+release-4.15+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:264]
kernel32
ntdll