Error 0x800721BC

Value: -2147016260 | 0x800721BC | 2147951036

What does it mean ?

ERROR_INVALID_USER_PRINCIPAL_NAME  
The User Principal Name (UPN) is invalid.
Value: 8636 | 0x21BC | 0b0010000110111100

Where does it come from ?

FACILITY_WIN32  
Provides a way to handle error codes from functions in the Win32 API as an HRESULT. (Error codes in 16 - bit OLE that duplicated Win32 error codes have also been changed to FACILITY_WIN32)
Value: 7 | 0x007 | 0b00000111

Other Errors for FACILITY_WIN32