Error 0x80072F7B

Value: -2147012741 | 0x80072F7B | 2147954555

What does it mean ?

ERROR_HTTP_HEADER_ALREADY_EXISTS  
The header could not be added because it already exists.
Value: 12155 | 0x2F7B | 0b0010111101111011
WININET_E_HEADER_ALREADY_EXISTS  
The HTTP header already exists
Value: 12155 | 0x2F7B | 0b0010111101111011

Where does it come from ?

FACILITY_WIN32  
Provides a way to handle error codes from functions in the Win32 API as an HRESULT. (Error codes in 16 - bit OLE that duplicated Win32 error codes have also been changed to FACILITY_WIN32)
Value: 7 | 0x007 | 0b00000111

Other Errors for FACILITY_WIN32