Hello! On our server we had Debian 4.0 installed and plesk 8.6.0, and about a week ago clients asked me to set up php 5 engine on machine. I used apt-get to install php5, as I remember it was plesk build of php. But after apt-get update/upgrade bunch of psa packets uninstalled. As I understood it was because of http://www.debian.org/News/2010/20100121 - Security Support for Debian 4.0 to be terminated. And I couldn't get psa uninstalled 8.6.0 packages back. So I decided to upgrade system to Debian lenny 5.0, I did that without serious problems. And then I tried to install psa 8.6.0 again and realized, that 8.6.0 version can not be installed on debian 5.0. So I installed newest version of plesk â€“ 9.5.2. And of course my old 8.6.0 key is not working for new version. And I donâ€™t know how to downgrade os back to debian 4.0. And I canâ€™t retrieve key through https://register.parallels.com/key_upgrade/ site and through plesk panel neither. Everything else is working normaly except Plesk panel â€“ it gives: â€˜Error: The license key is invalid. In order to use the Parallels Plesk Panel, please obtain and install a new functioning license key.â€™ What can I do to solve this problem? Do I have to buy new license?