This issue can be caused by one or both of the following items:

1. The "Most Recent Public Comment" or "Most Recent Public Comment HTML" merge field is not included in your email template(s).

Follow the steps outlined below to locate and review your email template(s) to ensure proper inclusion of the merge field.

1. Navigate to the Email to Case Premium Settings tab. By default, this should put you on the Outbound Configuration page.
2. Scroll down to the Email Templates section. Review the template specified in the "Default Email Template" setting, as well as the "Template Auto-selection Rules".
3. Cross-reference your email template(s) in Setup | Email | Classic Email Templates.
4. Locate the folder where your template(s) are located (typically the E2CP Templates folder).
5. Open you template(s), and ensure that the "Most Recent Public Comment" or "Most Recent Public Comment HTML" field is included.

2. Agent does not have access to "Most Recent Public Comment HTML" field.

Users working with the Enhanced Comment Editor will require access to the "Most Recent Public Comment HTML" field via field level security. The E2CP End User permission set (packaged with Email to Case Premium) already includes the necessary permissions. Please follow the steps outlined below to locate and assign this permission set.

1. Navigate to Setup | Users | Permission Sets.
2. Locate and Open the E2CP End User permission set.
3. Click Manage Assignments and then Add Assignments
4. Check the box next to all Email to Case Premium users in your Org, and click Assign.