I see an error when viewing my site that mentions the functions/oswc-post-types.php file

This means you have not fully filled out all of your review options for your review type. Go to Appearance >> Review Options and for each review type expand the panels and fill out the necessary fields. Pay particular attention to the Taxonomies, Rating Criteria, and Meta Fields, and make sure there are no blank fields. These are the minimum required fields for the review type to work.