Error 0x80EF01A4

Value: -2131820124 | 0x80EF01A4 | 2163147172

What does it mean ?

RTC_E_STATUS_CLIENT_BAD_EXTENSION  
Bad Extension
Value: 420 | 0x01A4 | 0b0000000110100100

Where does it come from ?

FACILITY_SIP_STATUS_CODE  
SIP - Session Initiation Protocol (VoIP)
Value: 239 | 0x0EF | 0b11101111

Other Errors for FACILITY_SIP_STATUS_CODE