EasyStore no longer backing up

My EasyStore WDBDNK0010B is no longer auto storing at the time I had set up for it. In fact, with my drive plugged into my laptop, when I double click the DW Backup icon, it doesn’t open. It looks like my C drive isn’t recognizing the external drive, and my question is why, what happened?

If it means anything, I have had instances towards the last of my auto backups that some file failed to back up. Could those files have anything to do with it?