Uncaught (in promise) Error: Failed to invoke 'XXXXX' due to an error on the server RRS feed

  • Question

  • User445468845 posted

    I created a .net core chat application using SignalR and I used WebRTC for video calls. As I need to send the SDP to the receiver using server method so I created a hub method call "SendOffer". When I click Video call button I have invoked this "SendOffer" method. I have put the client side code below

    var connection = new signalR.HubConnectionBuilder()
    const Peer = new RTCPeerConnection();
    const video = document.querySelector('video');
    const constraints = {
        'video': true,
        'audio': true
    document.getElementById("sendVideo").addEventListener("click", function (event) {
            video: true,
            audio: true,
        }).then(function (stream) {
            video.srcObject = stream
                .then(sdp => Peer.setLocalDescription(sdp))
                .then(function () {
                    //connection.invoke("SendOffer", Peer.localDescription).catch(function (err) {
                    //    return console.error(err.toString());
                    connection.invoke("SendOffer", Peer.localDescription);

    But this gives an error in the console log and not working. blow is the error

    signalr.js:2088 Uncaught (in promise) Error: Failed to invoke 'SendOffer' due to an error on the server. at _this.callbacks. (signalr.js:2088) at HubConnection.processIncomingData (signalr.js:2182) at WebSocketTransport.HubConnection.connection.onreceive (signalr.js:1905) at WebSocket.webSocket.onmessage (signalr.js:3949)

    Can any one please help me to solve this error.

    Sunday, April 5, 2020 9:47 PM

All replies

  • User711641945 posted

    Hi Janitha,

    The error message indicates that your server side makes error.Could you show error logs which is on your server side?

    Best Regards,


    Monday, April 6, 2020 9:37 AM
  • User445468845 posted

    Hi Rena

    the last part I have mention in the question is the error log that was given. But unfortunately I cant get the error back as code start to work correctly.  

    function CreatePeer() {   

            alert("Enter in to MakePeer");

            client.gotAnswer = false;

           let peer = InitPeer('init');

          // let data = null;</div> <div>           

           peer.on('signal', function (data) { 

                 if (!client.gotAnswer) {

                          connection.invoke('SendOffer', data);




    client.peer = peer;


    This was the code. when the pointer is in  "connection.invoke('SendOffer', data);"  this error was given.  So I call this part under the "let data =null". Then It was successfully run. I did it because in the error I saw websoket is received . But the guess makes the code right. But I don't have exact Idea why this happen. As you ask the console log I run the code keeping it as same above to take the error but now it is working. I think at that time some thing blocking must be happen.If you know can can you explain me and thanks for your reply 

    Tuesday, April 7, 2020 8:56 PM