A nonce error is an indication that you are being logged out during the update process.
1. Log out of your WordPress admin area
2. Log in here: http://www.everysaleonline.com/wp-login.php
3. On the log in page, check the "Remember Me
4. Go here: WordPress Admin Area > Tools > Datafeedr
5. Click the [Update Products and Settings] button.
See if that changes anything.