Moving from Supermint3Browser Info Environment
I haven't worked with that theme, but the chances are that it implemented areas with different names. Anyway, if there is a page type that has been widely used in a site, you will have a number of solutions to port it to another theme. One solution would be duplicating a new theme page type and change the 'area' name to the previously used area. You can also change the area name in the database directly if you know your way around the C5 database.
AND you can always count on our support if you need any.