EPUB not working on Pandigital Novel black


Apr 26, 2013
Hi, I have a Pandigital Black 7" with Terninater' firmware, and downloaded a free book from a site that has...free books. It is in an epub format but it doesn't show up on the B+N bookshelf. I figured this was because it wasn't a B+N book but I'm not sure. I put the file onto the sd card but when I try to eject the reader I get the error:

PD Novel is currently in use. Save any open files on this disk, and then close the files or the programs using the files before trying again.
If you continue, the files will be closed, which might cause data to be lost.

This would happen whether the novel was plugged into the computer using the usb cord or the sd card, the message is the same. I had some movies that caused (I think) parts of the sd card to become corrupt because the video would stop intermittently while the audio would continue. Also after I eject the novel after choosing the option to continue, the file still can't be read with B+N. Do I need another app to read books not bought thru Barnes and Nobel?