FACILITY_WIN32: This region is reserved to map undecorated error codes into HRESULTs.

This region is reserved to map undecorated error codes into HRESULTs.[1][2]See also the raw Win32 error codes.

Sources

  1. https://msdn.microsoft.com/en-us/library/cc231198.aspx
  2. winerror.h from Windows SDK 10.0.14393.0
  3. https://github.com/dotnet/coreclr/blob/v1.1.0/src/inc/corerror.xml