D365 for Ops System Email Template Setup - HTML vs. XSLT

We were getting an error in a workflow (Root element is missing) that leverages the System email template found in System administration>>Workflow>>Workflow parameters>>Email message. Note the references to HTML in the 'Upload email template' form below.  This would lead one to believe that the template uploaded must be in HTML format.

However, what we found was that during setup of this email template, XSLT was defaulted into the Layout field below.  The problem is, the Layout field is not exposed in this form by default.  We had to personalize the form to add the field.

The cause of the error was the mismatch between the Layout type (XSLT) and the HTML template that had been uploaded.  Once we discovered the mismatch and changed the Layout value to HTML, the email error was resolved.

Dynamics 365 for Operations - Disable User Session Date (System date)

While there are cases where you want users to be able to change their session date which controls the default Posting date on transactions, there are times such as immediately after Go Live, where you might not want new users to have that level of control. 

To disable users updating the session date for all users or a group of users, update System date security settings in the Client essentials security privilege.

Users will be able to see the Calendar object but not update their session date.