Error 0x80040050

Value: -2147221424 | 0x80040050 | 2147745872

What does it mean ?

TAPI_E_NOEVENT  
There is no event in the MSP's event queue.
Value: 80 | 0x0050 | 0b0000000001010000

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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