When Testing rTorrent fails during reboot or When rTorrent Repeatedly Crashes

If your reboot gets to "Testing rtorrent" within a few minutes, but stays there and eventually fails, it's likely rTorrent is crashing right after it starts.  Here's why and what to do:
 

Note: If there are no torrents or data loaded into rTorrent during a reboot, rTorrent will always run.

Corrupted .torrent file

Most of the time when rTorrent immediately crashes after starting it, it's because of a corrupted .torrent file in the .session directory where rTorrent stores them.  That's here:
 

To test and fix this,
 

1. Use SFTP to rename the .session directory to .session_bak
2. If there are any files in your .watch directory, make sure to rename it to .watch_bak as well.
3. Reboot your seedbox.  New .session and .watch directories with all the right specs will be created.

You should now see "Testing rTorrent" pass by just fine during the reboot.  Now you can start finding out which of the .torrent files is corrupted
 

1. Again using SFTP, move one .torrent file at a time from inside .session_bak into the .watch directory where rTorrent will automatically add them back into the .session directory and start them.  (TIP, if you prefer to move the .torrent files directly from .session_bak to .session, you just need to restart rTorrent each time to get it to register them.  You can restart rTorrent through SSH with this command: "/etc/init.d/rtorrent-[username] restart" or by rebooting your seedbox.)
2. If it continues to work, you know that .torrent file is not a problem, do the next one.
3. If rTorrent crashes when you move the .torrent file, you know that is a corrupted file and the cause of the problem.

Corrupted data or hidden file

If rTorrent will still not stay running after renaming the .session directory and rebooting, occasionally there can be corrupted data and/or hidden file causing rTorrent to crash - even if there are no .torrent files being loaded into rTorrent.
 

1. Do the exact same thing as above, only instead of renaming your .session folder, rename your whole rutorrent folder to rutorrent_bak (You will not lose any of your data. - Empty rutorrent and child directories will be created next reboot.) - So you will have: /data/[username]/rutorrent_bak/
2. Now reboot your seedbox one more time and you will find it passes the reboot step "Testing rTorrent" without a problem.
3. Again, follow the steps above to find out which and what data is causing the problem.

If rTorrent does not stay running with a freshly created and empty rutorrent folder, congratulations!  You've found a new species of bug eating the seed crops, please let us know! :)