network error

if i’v try to klik my web, there’s no open, just i’ve got alert like this :

“Network Error (tcp_error)

A communication error occurred: “Operation timed out”
The Web Server may be down, too busy, or experiencing other problems preventing it from responding to requests. You may wish to try again at a later time.

For assistance, contact your network support team.”

please, how to fix it ? thank’s