I found I could edit the server behaviors which already existed to add the coment field check back in. This at least restores the check to make sure the comment field is not left blank, and keeps the other fields values intact.
The problem is that I cannot add back the 'Validation Show If' which tell the user to enter a comment. If I do, the HTML field is completely eliminated.
Is there some way to simulate the 'Validation Show If' operation for the text box with HTML editor?
Also, is this now fixed on CSS Form Builder 2 which includes the HTML editor?