Error 0x80310059

Value: -2144272295 | 0x80310059 | 2150695001

What does it mean ?

FVE_E_VOLUME_HANDLE_OPEN  
BitLocker Drive Encryption is already performing an operation on this drive. Please complete all operations before continuing.
Value: 89 | 0x0059 | 0b0000000001011001

Where does it come from ?

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

Other Errors for FACILITY_FVE