Update: CE3 Cart 2.1.4 available
CE3 Cart 2.1.4 is now available. This update addresses a newly discovered bug with PayPal and sales totaling $1,000 or more.
The forum thread about this bug is here, for those interested.
To access the download, lookup your order using the "Find Your Order" section of the sidebar on this page. Your will need your order number and email address. Otherwise, look for an update notice to arrive via email.