EventSource failed loading signalr/connect

Question

Randomly, It happens that I'm not getting notifications via signalr and in Chrome console I can see:

EventSource failed loading: GET "https://my.website.net/signalr/connect?transport=serverSentEvents&clientProtocol=1.5&connectionToken=xxxxxxxxxxxxxxxxxxxxxxxxxx&connectionData=%5B%7B%22name%22%3A%22notificationhub%22%7D%5D&tid=3".

Any way to retry the connection or to understand where is the issue ?

I'm using ASP.NET SignalR JavaScript Library v2.2.2

Whelkaholism Whelkaholism · Accepted Answer · 2021-05-10T10:01:48

Chrome did a recent update that seems to have broken SignalR completely (typically, just as a client said "let's make the messaging system better!")

I have made a couple of changes which seems to have fixed the issue:

Update SignalR NuGet package to latest version (2.4.2)
Ensure the client-side script is the latest version if you are not using NuGet for client-side

Stick an auto-reconnect in if you don't have one:

    $.connection.hub.disconnected(function()
    {
        setTimeout(function()
        {
            $.connection.hub.start();
        }, 1000);
    });

Couple of related items:

https://www.reddit.com/r/dotnet/comments/mfkvj4/chrome_disconnects_signalr_hub/ https://github.com/SignalR/SignalR/issues/4536

EventSource failed loading signalr/connect

1 Answers