I am finally working with FMP12. In a new database file, when I create a new layout with all the table's fields, some of the fields will disappear from the layout if I select all the fields and remove their formatting. It is the same fields at every attempt.
I tried to narrow the behavior. Create a default layout with all fields. Pick one field (field name is "city"). Remove its formatting using the inspector. It and two other fields (that I have not edited) disappear!