Plesk remote ftp backup fails for the domains

Solution

https://support.plesk.com/hc/en-us/articles/360010535100-FTP-backup-fails-Cannot-create-a-file-when-that-file-already-exists

but with my remark:

Thank you for the quick fix. Helped for the domain backups. However, I have seen s slightly different error message but with the same effect:

Unable to create remote backup. Error: Unable to export backup: Transport error: Unable to create the directory ‘ftps://XXX.XXX/files/EXISTINGDIRECTORY/’: Curl error: (21) Quote command returned error: Last FTP request: MKD EXISTINGDIRECTORY Last FTP response: 550 Create directory operation failed.

There seems to be a difference between the remote FTP Backup Manager scripts for the domains and the plesk system. The scheduled FTP backups of plesk  (tools&settings-> backup manager) were working before and not affected.

Remark: The aforementioned update is working but the directory at the remote backup system must already exists, it will not be created if not.