Error 0x801901F6

Value: -2145844746 | 0x801901F6 | 2149122550

What does it mean ?

HTTP_E_STATUS_BAD_GATEWAY  
Bad gateway (502).
Value: 502 | 0x01F6 | 0b0000000111110110

Where does it come from ?

FACILITY_HTTP  
HTTP support
Value: 25 | 0x019 | 0b00011001

Other Errors for FACILITY_HTTP