Hey Joseph. Thanks for reaching out, and for your purchase of the PRO plugin. You can ignore that message – it was a problematic/inaccurate one that we had in the 2.0.7 version and below…but which was fixed in 2.0.8.
So long as you’ve got The Events Calendar 2.0.8 and Events Calendar PRO 2.0.8 installed on your site, you should be all set. Whether or not you have the license key in place, the plugin will function in its entirety (though no updates or support are available without the key).
Hope that helps. Let me know if you have any other questions on this or if I can elaborate at all. Cheers!