First off, try rebooting your computer. If that doesn't work, you may have a firewall or anti-virus program blocking the port so you wanna straighten that out. You may want to disconnect from the internet and disable your anti-virus stuff while rendering. If that doesn't work rendering from the comand line should do the trick.
"The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore all progress depends on the unreasonable man."
George Bernard Shaw - Man and Superman