- Plesk for Linux
No option to change document root for a website:
PLESK_INFO: It is impossible to change document root because there are web applications installed on this website.
This is an expected behavior as an application is using httpdocs directory to store it's own files. So if the document root for a website will be modified, the application will stop working. Plesk prevent such issues by restricting removing or changing default folder for a domain.
In order to change the document root, the application should be uninstalled.
Warning: as it may cause data loss, perform this on your own risk:
Open Subscriptions > example.com > Applications tab:
Select the application and remove it, e.g. Joomla: