Why node.js requires an upgrade while trying to run an application on the localhost?
<p>When I try to run my node.js application on a localhost server, it does not run and demands a required upgrade. I have tried to run the code but I get the following error:</p>

<p><a href="https://i.stack.imgur.com/ENyEV.png" rel="noreferrer"><img src="https://i.stack.imgur.com/ENyEV.png" alt="screenshot"></a></p>

<p><strong>server code</strong></p>

<pre><code> var WebSocketServer = require('ws').Server,
    ws = new WebSocketServer({port: 80}),
    CLIENTS=[];


**new connection etablished**
 ws.on('connection', function(conn) {
         CLIENTS.push(conn);
         conn.on('message', function(message) {
         console.log('received:  %s', message);
         sendAll(message);

    });


 console.log("new connection");
         conn.send("NOUVEAU CLIENT CONNECTE");

                **if you close connection**
         conn.on('close', function() {
           console.log("connection closed");
           CLIENTS.splice(CLIENTS.indexOf(conn), 1);
         });

    });
    **send messeages vers all clients**

function sendAll (message) {
    for (var i=0; i&lt;CLIENTS.length; i++) {
      var j=i+1;
      CLIENTS[i].send("Message pour le client "+j+": "+message);
    }
}
</code></pre>

<p><strong>client code</strong></p>

<pre><code>      &lt;p&gt;
        Result :&lt;output name="" type="text" id="result" value"readonly"&gt;&lt;/output&gt;
      &lt;/p&gt;
      &lt;input type="text" onchange="ws.send(this.value);"&gt;
      &lt;/body&gt;
      &lt;script&gt;
          var ws =new WebSocket('ws://localhost:80');
          ws.onmessage=function(event){
              document.getElementById("result").value=event.data;
          }
      &lt;/script&gt;
</code></pre>