Hi, we use your softphone but our customers can not call.. please help...

http://prntscr.com/gfueqe

VM108:161 WebSocket connection to 'wss://usrtcx.webvoipphone.com/mfstwebsock' failed: Connection closed before receiving a handshake response
WrappedWebSocket @ VM108:161
WsConnect @ lib_softphone.js:5
__tsip_transport_ws_start @ lib_softphone.js:5
__start @ lib_softphone.js:5
tsip_transport.start @ lib_softphone.js:29
tsip_stack.start @ lib_softphone.js:9
SIPml.Stack.start @ lib_softphone.js:30
Start @ lib_softphone.js:54
(anonymous) @ lib_softphone.js:54
lib_softphone.js:35 webphone: [16:25:24.141] WRTC, EVENT, __tsip_transport_ws_onerror 
lib_softphone.js:35 webphone: [16:25:24.142] WRTC, ERROR, WLIB, Websocket.onerror reaosn: undefined 
n @ lib_softphone.js:35
tsk_utils_log_error @ lib_softphone.js:1
__tsip_transport_ws_onerror @ lib_softphone.js:5
lib_softphone.js:35 webphone: [16:25:24.142] WRTC, EVENT, __tsip_transport_ws_onclose 
lib_softphone.js:35 webphone: [16:25:24.142] WRTC, ERROR, WLIB, Websocket.onclose: 1006; reason:  
n @ lib_softphone.js:35
tsk_utils_log_error @ lib_softphone.js:1
__tsip_transport_ws_onclose @ lib_softphone.js:5
lib_softphone.js:35 webphone: [16:25:24.146] WRTC, EVENT, ==stack event = failed_to_start 
lib_softphone.js:35 webphone: [16:25:24.147] ERROR,-1,Register failed 
n @ lib_softphone.js:35
onSipEventStack @ lib_softphone.js:55