When trying to upgrade a WordPress plugin, the upgrade fails with error:
Update failed: Failed to connect to SSH2 Server localhost:22
I checked my ftp user permissions to folders and its credential in wp-config.php.
Everything looks right. But, the error still persists.
Please make sure your server port 22 is open:
sudo ufw allow 22
You can disable the rule after finishing the upgrade:
sudo ufw delete allow 22