failed to connect signalR error during websocket handshake code : 400

Question

i have signalR websocket to show notification

the code for connecting like :

$.connection.hub.start().done(function(){
  console.log("connected");
});
            
var notif = $.connection.notificationHub;
console.log(notif);

after deploying to a production server signalR is not working and showing this error in console :

production server is using iis 8.5 what makes this error? thank you.

Answer 1

Do you have this tag in your web.config file within the <system.web> tag?

<httpRuntime maxRequestLength="40960" targetFramework="4.5" requestValidationMode="2.0" />

If that doesn't work try failing over to long polling instead of WebSockets in SignalR and see if you get the same error.