Error 0x80310047

Value: -2144272313 | 0x80310047 | 2150694983

What does it mean ?

FVE_E_FS_NOT_EXTENDED  
This drive cannot be encrypted by BitLocker Drive Encryption because the file system does not extend to the end of the drive. Repartition this drive and then try again.
Value: 71 | 0x0047 | 0b0000000001000111

Where does it come from ?

FACILITY_FVE  
Full volume encryption
Value: 49 | 0x031 | 0b00110001

Other Errors for FACILITY_FVE