This error normally occurs when a client sends a request to the server, and the request is timed out on the server. Their are lot of possibilities caused that can create this error, most common cause is your local issues only, that is due to proper internet connection or any local firewall issues. If everything is fine with local end then their is also a chance for the error is server related and the case is when a huge traffic coming to server and your request gets hampered may cause this error.