hey all   I am trying to get my Ipac2 with buttons to work with my retropie emulators. It is working great with any mame games however when I try to use anything else it wont work.  I thought I could go into the cd /opt/retropie/configs/all      then nano retro arch.cfg   the fisrt time I managed to go into the file and see the key mapping    I did not make any changes, my keyboard was not responding so I unpluged my Pi and then the next time I went into the same location EVERYthing in the file is gone.    What did I do, how can I fix it.