The error of payload to big is in the websocket protocol, you will avoid that problem if you disable websockets in /var/www/html/fop2/js/presence.js or by using the latest 2.27 version. You do not say if you updated fop2 or not already? In any case, the payload size seems *too* big for a normal fop2 packet. Did you upgrade to 2.27?

If you saw the payload too big error, then websockets was NOT disabled, as it is an exclusive error of a browser connecting over websockets. Take into account that the presence.js file can be cached in the browser , so the setting won't do any effect until the browser reloads that file from the server.

Best regards,