stack trace is as follows:
LogWindows: Error: Assertion failed: GIsEditor || bCreatingCDO || !InClass->HasAnyClassFlags(CLASS_Abstract) [File:D:\Build++UE4\Sync\Engine\Source\Runtime\CoreUObject\Private\UObject\UObjectGlobals.cpp] [Line: 2340]
[2019.10.16-21.02.30:441][ 0]LogWindows: Error:
[2019.10.16-21.02.30:441][ 0]LogWindows: Error:
[2019.10.16-21.02.30:441][ 0]LogWindows: Error:
[2019.10.16-21.02.30:441][ 0]LogWindows: Error: [Callstack] 0x00007ff9801ea839 UnknownFunction []
[2019.10.16-21.02.30:441][ 0]LogWindows: Error: [Callstack] 0x00007ffebf52a000 UnknownFunction []
[2019.10.16-21.02.30:441][ 0]LogWindows: Error: [Callstack] 0x0000000000000400 UnknownFunction []
[2019.10.16-21.02.30:441][ 0]LogWindows: Error: [Callstack] 0x0000004d36acabd0 UnknownFunction []
[2019.10.16-21.02.30:441][ 0]LogWindows: Error: [Callstack] 0x00000000ffffffff UnknownFunction []
[2019.10.16-21.02.30:441][ 0]LogWindows: Error: [Callstack] 0x0000000000000001 UnknownFunction []
[2019.10.16-21.02.30:441][ 0]LogWindows: Error:
[2019.10.16-21.02.30:465][ 0]LogExit: Executing StaticShutdownAfterError
[2019.10.16-21.02.30:469][ 0]LogWindows: FPlatformMisc::RequestExit(1)
[2019.10.16-21.02.30:473][ 0]Log file closed, 10/16/19 16:02:30