SignalR getting 403 on AppHarbor after updating to v. 1.0.1 (Chrome) - asp.net-mvc-4

Question

I was using SignalR v. 1.0.0 RC2, and it worked fine. When I upgraded to v. 1.0.1 it stopped working. I am now getting a 403 (forbidden) when I am trying to invoke a method on the hub. I did not change any code - I only updated to the newer version of SignalR. It is important to note that I do not have any problems when I run it locally - only when I run it on AppHarbor, and only in the Chrome browser. It works in IE 10 and Firefox 20.
I know that some work has been done in the newer version of SignalR for authorization. Now you can add an Authorize attribute on your hub, or your hub methods. I want to do that, but first I would like it to work without - like it did before.
This is my hub:
using System.Threading.Tasks;
using Microsoft.AspNet.SignalR;
public class ReceptionHub : Hub
{
public Task Join(string group)
{
return Groups.Add(Context.ConnectionId, group);
}
}
And this is the client site script (I get the group from a data attribute in the markup):
$(function () {
var receptionHub = $.connection.receptionHub;
receptionHub.client.updateStatusBar = function (checkedIn, checkedOut, preRegistered)
{
$('#quantityCheckedInToday').html(checkedIn);
$('#quantityCheckedOutToday').html(checkedOut);
$('#quantityPreRegistered').html(preRegistered);
};
$.connection.hub.start().done(function () {
var group = $("#statusBar").data("group");
receptionHub.server.join(group);
});
});
One difference between my local setup and the setup on AppHarbor is that I run the AppHarbor site on HTTPS, but that was not a problem before. Also, there is a loadbalancer infront of the server on AppHarbor.
The request that fails is a POST request to this URL:
/signalr/send?transport=serverSentEvents&connectionToken=5hSSl7wSPrkD51cmPNw-JCrrdxMn2qOgEgmKt5gKrE4jigE4Sxha3gALHREcyDslqb7xjY9fP8rTMpslKuBJzBCIi-q86ZmHt66xhqi2eioAtvQCO03XlcR0Dq9-RW5G0
Any help is much appreciated

Answer 1

I have now tried using SignalR 1.1.2 - and it still did not work in Chrome, but this time it gave a much better error message. It said that CORS was turned off. I tried turning CORS on in the configuration:
var config = new HubConfiguration
{
EnableCrossDomain = true
};
// Register the default hubs route: ~/signalr
RouteTable.Routes.MapHubs(config);
This fixed the problem I was having, and now it works again in Chrome. I am not sure why CORS needs to be turned on to get it working in Chrome... maybe some special AppHarbor setup.