Ran into this one today. A site with only SFTP/SSH access, and the server required the “FTP” method of updating plugins/WordPress. Remember FTPS is not SFTP. FTPS runs over HTTPS/SSL, while SFTP runs over SSH. Confusing? Fortunately there’s a nice little plugin called, SSH SFTP Updater Support. You must download it, then upload the contents [...]
Help: I only have SFTP/SSH access, How can I update my WordPress plugins? is a post from: Sean Walther's Blog