- Plesk for Linux
While accessing the Backup Manager at Tools & Settings > Backup Manager:
PLESK_WARN: Warning: Some of the files in the FTP storage are not shown in the list because the names of those files do not conform to the naming convention of backup files. If you are sure that those files are valid backups, rename them to match the following pattern: "backup_<YYMMDDHHmm>.tar"
Files not related to Plesk backup are stored on FTP server in the same folder as Plesk backups.
Remove or move files not related to Plesk backup from FTP storage folder.