Failure to Connect to the Mediation Server in LogMeIn Hamachi usually is a result of one of the following:
Local or network firewall blocking the communication.
You are behind a proxy server.
The computer’s Domain Name Service cannot resolve the website.
In either of the first two cases, Hamachi is unable to connect to bibi.hamachi.cc on TCP port 12975. This is the default connection port for communication to the mediation server. If this fails, Hamachi tries to connect via SSL on the default port of TCP 443. You'll need to either configure your firewall, or, if applicable, input your proxy settings into Hamachi Preferences > Settings.
In the third case, ensure your computer (and router if applicable) are configured to use the DNS settings as outlined by your ISP. If you run
tracert charlie.hamachi.cc > c:\trace.txt from the command line and send us this file, we will be able to give you a better idea of what is going on.