I'm having an error that the connection has timed out and that the server is taking too long in order to respond , from Firefox 50 :
The connection has timed out
The server at ca.rles-tub.io. is taking too long to respond.
The site could be temporarily unavailable or too busy. Try again in a few moments.
If you are unable to load any pages, check your computer’s network connection.
If your computer or network is protected by a firewall or proxy, make sure that Firefox is permitted to access the Web.