LogDuringMapLoad

[2018.03.01-11.14.56:457][  1]LogNet: Browse: MAPNAME
[2018.03.01-11.14.56:457][  1]LogLoadingSplash: Loading begins
[2018.03.01-11.14.56:532][  1]LogHMD: FSplash::OnShow
[2018.03.01-11.14.56:532][  1]LogLoad: LoadMap: MAPNAME
[2018.03.01-11.14.56:582][  1]LogWindows: Windows GetLastError: The operation completed successfully. (0)
[2018.03.01-11.14.56:874][  1]LogWindows: Error: === Critical error: ===
[2018.03.01-11.14.56:874][  1]LogWindows: Error:
[2018.03.01-11.14.56:874][  1]LogWindows: Error: Fatal error: [File:D:\Build\++UE4+Release-4.18+Compile\Sync\Engine\Source\Runtime\CoreUObject\Private\Serialization\AsyncLoading.cpp] [Line: 6647]
[2018.03.01-11.14.56:874][  1]LogWindows: Error: LoadPackageAsync failed to begin to load a package because the supplied package name was neither a valid long package name nor a filename of a map within a content folder: ''
[2018.03.01-11.14.56:874][  1]LogWindows: Error:
[2018.03.01-11.14.56:874][  1]LogWindows: Error:
[2018.03.01-11.14.56:874][  1]LogWindows: Error: [Callstack] 0x0000000098CB4008 UnknownFunction []
[2018.03.01-11.14.56:874][  1]LogWindows: Error: [Callstack] 0x00000000C957A000 UnknownFunction []
[2018.03.01-11.14.56:874][  1]LogWindows: Error: [Callstack] 0x0000000000000400 UnknownFunction []
[2018.03.01-11.14.56:874][  1]LogWindows: Error: [Callstack] 0x000000002E2CAF20 UnknownFunction []
[2018.03.01-11.14.56:874][  1]LogWindows: Error: [Callstack] 0x000000002207B448 UnknownFunction []
[2018.03.01-11.14.56:874][  1]LogWindows: Error: [Callstack] 0x0000000000000001 UnknownFunction []
[2018.03.01-11.14.56:874][  1]LogWindows: Error: [Callstack] 0x0000000000000001 UnknownFunction []
[2018.03.01-11.14.56:874][  1]LogWindows: Error:
[2018.03.01-11.14.56:890][  1]LogExit: Executing StaticShutdownAfterError
[2018.03.01-11.14.56:891][  1]LogWindows: FPlatformMisc::RequestExit(1)
[2018.03.01-11.14.56:891][  1]Log file closed, 03/01/18 11:14:56