Error 0x80040031

Value: -2147221455 | 0x80040031 | 2147745841

What does it mean ?

TAPI_E_DROPPED  
The call was disconnected.
Value: 49 | 0x0031 | 0b0000000000110001

Where does it come from ?

FACILITY_ITF  
COM/OLE Interface management. FACILITY_ITF is designated for user-defined error codes returned from interface methods
Value: 4 | 0x004 | 0b00000100

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