From January 1st, 2018 Plesk will discontinue the availability of Plesk 10.x/11.x licenses that differentiate on number of domain support. All currently active Plesk 10.x/11.x licenses will remain active and continue to renew on a monthly basis, though since the effective date it will not anymore be possible to restore Plesk legacy licenses via neither Openprovider customer service, nor Plesk support. Therefore, if you have legacy licenses in your portfolio make sure you have enough credit on your account balance for monthly renewal, which will keep your licenses safe and prevent from termination.
In case you have not adopted the new Web Edition licensing model yet, you can be acquainted with them here.
In case if you face an issue after 1st of Jan, 2018 and you’ve removed the license by mistake then there are still few options. If the software version of Plesk is already Plesk 12 or higher, simply replace the legacy license with a Web Edition license. If the software version is still Plesk 10.x/11.x, please contact us and we will request a temporary license from Plesk so you have enough time to update your server to Plesk 17.5.
Please note that Plesk 10.x/11.x licenses reached EOL status in December 2016 according to Plesk life-cycle policy and should be phased out gradually.