Templates not loading into mail notifications

Since the upgrade to WP 4.5, WP_Invoices is no longer loading in templates into the mail to the client (the invoices no appear blank with no body, password or login). More specifically, the subject and content would auto-fill from the appropriate template when clicking “send notification” and selecting “New Invoice” (or any of the templates). The template would calculate the total (%amount%) and display it in the body, but this is no longer happening.

https://www.ads-software.com/plugins/wp-invoice/