Check the display settings, go through different variants. If the 'Custom Place' setting is selected, make sure you have made the necessary changes in the page's code. See whether reviews are displayed on the page having disabled our extension, maybe your theme doesn't support reviews.
You might have forgotten to set up ratings in Magento. If you want to create your own custom rating, which is to be displayed in catalog lists on a product page, go to Admin Panel>Catalog>Reviews and Ratings > Manage Ratings. Then click the 'Add New Rating' button and configure the default rating values in keeping with your needs.