Error 0x80310056

Value: -2144272298 | 0x80310056 | 2150694998

What does it mean ?

FVE_E_HIDDEN_VOLUME  
The hidden drive cannot be encrypted.
Value: 86 | 0x0056 | 0b0000000001010110

Where does it come from ?

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

Other Errors for FACILITY_FVE