Hi Sue,
If you first publish your metadata (Settings > ClickDimensions Settings, click on "Metadata") prior to upgrading, you should be fine. The problem in CRM 2015 prevents us from getting the list of your custom fields for the Account, Contact and Lead entities, so we cannot make them available for personalizing email templates or for mapping form fields. But if you publish the metadata prior to upgrading to CRM 2015, these functions should continue to work fine.