The Plesk self-repair functionality enables you to automatically diagnose and resolve issues with Plesk and Plesk services. If you encounter an issue with one of the Plesk services (for example, if mail is not being sent or delivered, or a website fails to open, and so on), or with Plesk itself (for example, if error messages are being displayed in the Plesk interface, or if Plesk pages fail to load), you can use the Plesk repair utility to attempt to resolve it. The utility can be used to check and repair individual aspects of Plesk (such as the mail service, or the Plesk database), or all the aspects at once.

More at https://docs.plesk.com/en-US/12.5/administrator-guide/plesk-administration/plesk-repair-utility.74649/