The Kindle Reader in Kindle fire is responsible of the Books and Docs views in the original Kindle Fire interface. An update to the Kindle reader through the Android market place will corrupt it, making it incompatible and thus, making the Books and Docs views empty.
Luckily, there is a fix to this, all you need to do is to rollback the Kindle reader by removing the update installed through the market place. This is done by going to settings, applications, then finding Amazon Kindle , there should be an option there to uninstall update. do it.
Thats it your Kindle fire’s default interface should be working again.