Duplicati cannot backup to SSH on Debian after remote server upgrade (algorithm negotiation error)

Question

This issue may be relevant for other Duplicati users:

Duplicati is configured to back up via SSH to the Debian web server. After updating this web server, the backup failed with the error message "Algorithm negotiation error."

SFTP through FileZilla is still possible using the same credentials.

Answer 1

The problem is that "unsafe" algorithms were disabled for SSH (in 2014/15): fooobar.com/questions/176599 / ...

(. ). ( ) SSH, :

• psftp.exe PuTTY.
• Duplicati " Duplicati" → "SSH" pdftp.exe SFTP.
• "Duplicati Assistant", , SFTP.

, " " " ". , -.