I have deactivated all plugins and still receive the error. Leads me to think it is the WooCommerice Authorize.net AIM Plugin.
It says it is version 3.7 and fully updated on the WP Plugin page, but when I go to this page:
/wp-admin/admin.php?page=wc-status
It says this:
WooCommerce Authorize.net AIM Gateway by WooThemes / SkyVerge – 3.7.0 – 3.10.1 is available