Using Integer Bitmask crashes editor

attempting to open a project with Bitmask Flags set to true in a blueprint crashes editor.

Note In attached project, the crash has been narrowed down to the filepath \Content\ThirdPersonBP\Blueprints.

Frequency 4/4

Crashreporter [Link Removed]

1. Download, Unzip, Open project at link:

[Link Removed]

Results

Editor crashes

Expected

Editor opens

MachineId:409D523543AE785961A2788C698A2F90
EpicAccountId:2e342bbd0e92480fa71bf4505b6a81c3

Assertion failed: EntryIndex != INDEX_NONE [Link Removed] [Line: 156]

UE4Editor_Core!FDebug::AssertFailed() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\core\private\misc\outputdevice.cpp:440]
UE4Editor_Engine!FBPVariableDescription::GetMetaData() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\engine\private\blueprint.cpp:157]
UE4Editor_UnrealEd!FBlueprintEditorUtils::ValidateBlueprintVariableMetadata() [d:\build\++ue4+release-4.12+compile\sync\engine\source\editor\unrealed\private\kismet2\blueprinteditorutils.cpp:5262]
UE4Editor_Engine!UBlueprint::Serialize() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\engine\private\blueprint.cpp:364]
UE4Editor_CoreUObject!FLinkerLoad::Preload() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\linkerload.cpp:3293]
UE4Editor_CoreUObject!FLinkerLoad::RegenerateBlueprintClass() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\blueprint\blueprintsupport.cpp:352]
UE4Editor_CoreUObject!FLinkerLoad::FinalizeBlueprint() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\blueprint\blueprintsupport.cpp:1319]
UE4Editor_CoreUObject!FLinkerLoad::Preload() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\linkerload.cpp:3340]
UE4Editor_CoreUObject!FLinkerLoad::CreateExport() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\linkerload.cpp:3978]
UE4Editor_CoreUObject!FLinkerLoad::IndexToObject() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\linkerload.cpp:4187]
UE4Editor_CoreUObject!FLinkerLoad::CreateExport() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\linkerload.cpp:3682]
UE4Editor_CoreUObject!FLinkerLoad::CreateExportAndPreload() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\linkerload.cpp:2780]
UE4Editor_CoreUObject!FLinkerLoad::LoadAllObjects() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\linkerload.cpp:2919]
UE4Editor_CoreUObject!LoadPackageInternal() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:1162]
UE4Editor_CoreUObject!LoadPackageInternal() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:1286]
UE4Editor_CoreUObject!FLinkerLoad::VerifyImportInner() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\linkerload.cpp:2457]
UE4Editor_CoreUObject!FLinkerLoad::VerifyImport() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\linkerload.cpp:2212]
UE4Editor_CoreUObject!FLinkerLoad::VerifyImportInner() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\linkerload.cpp:2505]
UE4Editor_CoreUObject!FLinkerLoad::VerifyImport() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\linkerload.cpp:2212]
UE4Editor_CoreUObject!FLinkerLoad::VerifyImportInner() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\linkerload.cpp:2505]
UE4Editor_CoreUObject!FLinkerLoad::VerifyImport() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\linkerload.cpp:2212]
UE4Editor_CoreUObject!FLinkerLoad::Verify() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\linkerload.cpp:1995]
UE4Editor_CoreUObject!FLinkerLoad::FinalizeCreation() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\linkerload.cpp:1905]
UE4Editor_CoreUObject!FLinkerLoad::Tick() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\linkerload.cpp:704]
UE4Editor_CoreUObject!FLinkerLoad::CreateLinker() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\linkerload.cpp:428]
UE4Editor_CoreUObject!GetPackageLinker() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\linker.cpp:613]
UE4Editor_CoreUObject!LoadPackageInternal() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:1087]
UE4Editor_CoreUObject!LoadPackageInternal() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:1286]
UE4Editor_UnrealEd!UEditorEngine::Map_Load() [d:\build\++ue4+release-4.12+compile\sync\engine\source\editor\unrealed\private\editorserver.cpp:2397]
UE4Editor_UnrealEd!UEditorEngine::HandleMapCommand() [d:\build\++ue4+release-4.12+compile\sync\engine\source\editor\unrealed\private\editorserver.cpp:5987]
UE4Editor_UnrealEd!UEditorEngine::Exec() [d:\build\++ue4+release-4.12+compile\sync\engine\source\editor\unrealed\private\editorserver.cpp:5477]
UE4Editor_UnrealEd!UUnrealEdEngine::Exec() [d:\build\++ue4+release-4.12+compile\sync\engine\source\editor\unrealed\private\unrealedsrv.cpp:744]
UE4Editor_UnrealEd!FEditorFileUtils::LoadMap() [d:\build\++ue4+release-4.12+compile\sync\engine\source\editor\unrealed\private\filehelpers.cpp:2135]
UE4Editor_UnrealEd!FEditorFileUtils::LoadDefaultMapAtStartup() [d:\build\++ue4+release-4.12+compile\sync\engine\source\editor\unrealed\private\filehelpers.cpp:3349]
UE4Editor_UnrealEd!FUnrealEdMisc::OnInit() [d:\build\++ue4+release-4.12+compile\sync\engine\source\editor\unrealed\private\unrealedmisc.cpp:300]
UE4Editor_UnrealEd!EditorInit() [d:\build\++ue4+release-4.12+compile\sync\engine\source\editor\unrealed\private\unrealed.cpp:89]
UE4Editor!GuardedMain() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\launch\private\launch.cpp:137]
UE4Editor!GuardedMainWrapper() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:126]
UE4Editor!WinMain() [d:\build\++ue4+release-4.12+compile\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:200]
UE4Editor!__scrt_common_main_seh() [f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:264]
kernel32
ntdll