Automated Emails Not Working "Email could not be sent automatically because this record has multiple contact roles"

Overview

You have created a Play were emails are sent out automatically but you are receiving a message from Automated Emails, which had worked perfectly in the past:  
Email could not be sent automatically because this record has multiple contact roles

Information

This error occurs when an automated email is created for an Account record with multiple Contacts.
Please note that earlier there was a functionality that picked one of the Contacts linked to the Account to send an automated email to, which has been changed in 2021 to the following logic (that is applied to any custom objects):
If there is a single contact linked to an account, an automated email is sent out successfully; if there are multiple linked contacts, an email won't be sent.

Note: If you would like to change this functionality, you can submit an enhancement request to our support team.