Error 0x8031004C

Value: -2144272308 | 0x8031004C | 2150694988

What does it mean ?

FVE_E_TOKEN_NOT_IMPERSONATED  
The access token associated with the current thread is not an impersonated token.
Value: 76 | 0x004C | 0b0000000001001100

Where does it come from ?

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

Other Errors for FACILITY_FVE