This plug-in is important because it works with creating the custom fields for your pages like the contact us and the list your business pages. The fields that your client will fill out is generated by this plugin. Make sure you have this installed and activated.
If you need help installing it, you can watch the tutorial: http://members.wpmobidirectories.com/members-area/tutorials/video-1-the-basics/ or check page 5 of the pdf file version of the tutorial http://members.wpmobidirectories.com/members-area/tutorials/pdf-manual/. Make sure you are logged in to your member's area to view these.