Hello, @barryhynd,
Please go to Porto > Dashboard, then unregister your theme license. After that, re-register the license using the same purchase code and try again.
If the issue still persist, then please share your site WP Admin URL and Credentials with us under the private content area of this topic, so that we can have a look into it for you on your site and help you out.
Best Regards,
PThemes Team.