QuFTP Service 1.4.4 having issues with PLESK Backup Manager

English General
1

Hello, I have a TS-231P3 with QTS 5.2.9.3451, running latest compatible QuFTP Service, version 1.4.4, which was automatically updated from version 1.4.3 on April 3rd, 2026 (1.4.4 was available since April 2nd, 2026).

I use QuFTP service to create a FTPS server, which is accessed by a Plesk server to perform a daily backup of the whole server. It has worked flawlessly for years, no hiccups whatsoever.

Since the day of install, April 3rd, 2026, Plesk started reporting issues when finalizing the backup to the QuFTP server, with errors like:

“pmm-ras failed (Error code = 1): Repository error: Failed to read backup XXX.tar: Import error: Unable to find archive metadata. The archive is not valid Plesk backup or has been created in an unsupported Plesk version”.

and

“Export error: Size of volume XXX.tar 20805223935 does not match expected one 20806575198. The remote backup may not be restored.; Unable to validate the remote backup. It may not be restored. Error: Failed to exec pmm-ras: Exit code: 119: Import error: Unable to find archive metadata. The archive is not valid Plesk backup or has been created in an unsupported Plesk version”.

No backup is thus created by Plesk.

Only the backup process to QNAP FTP service fails, other PLESK backup solutions (like backupping to the local storage or other FTPS solutions) do work as expected. Therefore PLESK is not to blame for the issue.

I think the QuFTP 1.4.4 version broke something: the issue began the day of the QuFTP 1.4.4 update, April 3rd , 2026.

2

Have you tried rolling back to the version that was working?

(and maybe disable automatic updates)

3

Hello,

I tried to look for the 1.4.3 version on QNAP download center to download and manual install it but I could not find find any link to that specific version.

4

Ok, I was able to revert back to QuFTP version 1.4.3 by looking at how the download URL is structured, and by guessing the publishing date of that version (which is part of the link). The PLESK backup now works with this version, therefore version 1.4.4 is definitely bugged.