Problem Reading eBooks on Kindle Fire HD

I’m using the 32GB Connect with a Kindle Fire HD 8.9. I have a library of unprotected ebooks that use the .mobi file format. Many are from Project Gutenberg. I have never had any problem loading them from my computer to the Fire then opeining them up and reading them.

When I got my Connect, I removed all these .mobi ebooks from my Fire by connecting the Fire to my computer with a usb cable and using Windows Explorer to quickly delete them. Then I connected my Connect to my computer and copied the ebooks to the Connect’s Non-Kindle Books folder which I created. After disconnecting the Connect from my computer, opening the Connect app on my Fire and starting the Connect, I tried to open one of the books. Instead of opening, I got an error message: “Cannot View Item – Your Android device cannot view this type of file.” Obviously, that message is incorrect. Nevertheless, I couldn’t open the book directly from the Connect, so next I decided to download the book to the Fire and try to open it from the Fire directly. Same error message.

What am I doing wrong? Or, what steps have I missed to set up the Connect to allow reading of unprotected .mobi files, either from the Connect, or from the Fire after being downloaded from the Connect?

Thanks in advance for any help.