Hi,
1. i understand you are seeing the error message with login/register links when viewing a page with [adverts_add]?
If so then in most cases the problem is that the quote characters are converted to the UTF-8 signs which makes it impossible for shortcode to recognize the params.
What you can try doing is go to wp-admin / Pages panel edit the page with [adverts_add] if you are using a classic editor click “Text” tab in the text editor and type the shortcode again from the keyboard.
If you are using Gutenberg, add a Shortcode Block and type the shortcode from keyboard there.
2. we do not have an export functionality but you can use some third party export plugin like WP All Export to export the user Advert custom post type data.
We also have a GDPR compatibility snippet for WPAdverts, it will allow you to list all terms and conditions, privacy policies and etc. on the [adverts_add] page and force user to accept the selected ones
The snippet you can find here https://github.com/simpliko/wpadverts-snippets/blob/master/gdpr-compliance-for-wpadverts/gdpr-compliance-for-wpadverts.php how to install it you can read here https://github.com/simpliko/wpadverts-snippets/ at the bottom of the page.
