Error 0x800721C3

Value: -2147016253 | 0x800721C3 | 2147951043

What does it mean ?

ERROR_DS_LOW_ADLDS_FFL  
The functional level of the AD LDS configuration set cannot be raised to the requested value, because there exist one or more ADLDS instances that are at a lower incompatible functional level.
Value: 8643 | 0x21C3 | 0b0010000111000011

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