I restored a backup from a Windows 8 Pro (that was working fine) for a Windows Server 2012 of my 3CX Phone System. On my Windows 8 Pro my firewall checker did everything ok. But now in my Windows Server 2012 I had some problems with my fowarding ports, the firewall checker are saying: “Failed – Malformed or no response received from configured STUN servers. Check your internet connection, DNS settings, or change STUN servers from Settings > Network > STUN Server tab.” I fowarded all the ports that i need using this link: http://www.3cx.com/blog/docs/ports-used/ And allow the access in my Windows Server firewall, but it still not working. I used this link to check each port: http://www.yougetsignal.com/tools/open-ports/ I saw that the ports 5000 and 5060 are fowarded, the others as 5090 (for the tunnel) and 9000-9049 are closed. Anyone had this problem with Windows Server 2012? Everything is working fine, only this is my problem now. Thanks, Caio Vinicius.