Symptoms

Parallels Plesk Panel is unable to retrieve license key. The following error appears when click button "Retrieve Keys" on the License Management page:


Licensing Server Unreachable: Unable to connect with licensing server.
Please make sure that your network allows communication to ka.parallels.com:5224.
For more details check system help pages.

What causes the problem?

Resolution

Parallels Plesk Panel connects Parallels License Server (Key Administrator) at 5224 port for the license update procedure. Make sure that the outgoing connection to ka.parallels.com:5224 is not blocked on Plesk server or somewhere in the net. This can be examined with commands:

If you find that ka.parallels.com:5224 is not accessible from the server, try to stop firewall (iptables) and try to retrieve the key with the "Server -> License Management -> Retrieve Keys" button. If not, probably you should contact your ISP to open the port.