Hi Graham,
Thank you for getting in touch to report the issue. I believe you have run into a known bug in 3.0.2 that affects anyone with a database table prefix other than the default of wp_. Happily, we’ve been working hard to get a fix and ] just released Events Calendar PRO 3.0.3, which addresses this issue. Please update your plugin and that should resolve the issue. If you are still having problems, certainly let us know. Thank you all for your patience while we got this fixed!
To upgrade to a license that can be used on multiple sites, head over to tri.be and login to your account. Navigate to Account Central –> License Keys and you’ll see your key listed. Next to it you have a link for Upgrading to a Business License (3 sites) or a Developer License (10 sites). If you need any help with that process, just let me know.
Cheers,
Leah