Impossible to delete "failed" or "finished with warnings" backups stored on the remote FTP storage

Symptoms

• It is not possible to delete "failed" or "finished with warnings" backups stored on the remote FTP storage
• Backup checkboxes are not selectable and display the following message when hovering the mouse pointer: "The backup cannot be removed because it is a part of a server, reseller, or customer backup".

• /var/log/plesk/PMM/migration.log contains the following

  CONFIG_TEXT: INFO: Ftp init url ftps://ftp.domain.tld//backups/backup_example.com_2006030233.tar
  INFO: ImportError Import error: Unable to find archive metadata. The archive is not valid Plesk backup or has been created in an unsupported Plesk version [common/plesk-utils/PMM/repository-transport/PackedDumpHeader.cpp:ImportError]

Cause

Corrupted backup file

Resolution

In order to fix it, the following can be done:

1. Manually, using some FTP client, move out from folder where Plesk backups located or delete from the remote FTP storage all the files matching pattern *example.com_2006030233*

   Note: Pattern can be extracted from the error message.

2. Log in to Plesk

3. Go to Tools & Settings > Backup Manager, and close the message "backup ** was created and can be restored, although some minor issues occurred" and reload the page.

Additional information

Backup structure in Plesk for Linux