Note: The issue only occurs with Plesk installed on Virtuozzo containers.
I have a container with Plesk 10 (not the latest version) installed. I installed a "pp-webmail" template to it and later realized that the Plesk installation was upgraded to version 11 during that process. How could that happen?
Since the release of version 10, Plesk has adopted the following naming conventions:
pp-\ (e.g., "pp-webmail" or just "pp" for PP) – The latest, cutting-edge version of the Plesk control panel. Currently, it is Plesk 11.5.30, but with releases of new updates, installing the pp-\ template will install the latest available version of Plesk.
ppX-\* (e.g., "pp10") – The latest version in the line of Plesk X . Currently, it is Plesk 10.4.4 for pp10 and Plesk 11.0.9 for pp11 . Thus, when you install the pp-webmail template, it requires the latest Plesk version, due to dependencies and leads to a Plesk upgrade.
Do not install version-free templates unless you are running the latest Plesk version. In this particular case with webmail you should use
pp10-webmail instead of