Firewall. While you wait to join, use alt+ctrl, then delete while holding it(this in fullscreen, will bring down the srb2 window). Then if their is no "Allow srb2 to access the internet?"(but most likely it will show up. If it does, ignore rest of my post), go to your virus protection provider window, go to firewall, and choose program rules. If you see Srb2, look next to it, usually at the other side. As a rule of thumb for most firewalls, red=no, green=yes, if it is red, click the srb2 line once, and you should be able to collect the green option below.