If you are getting
No connection to rTorrent. Check if it is really running. Check $scgi_port and $scgi_host settings in config.php and scgi_port in rTorrent configuration file
Delete /home/rtorrentuser/rtorrent/session/rtorrent.lock file.
Then either you restart rtorrent by doing /etc/init.d/autodl_(username) restart
start a new rtorrent instance (if it never got started) by doing screen -fa -d -m -S rtorrent rtorrent