Hello Denorme

Thank you for your purchase.

Are you trying to create a new table, or did you click on an existing table, and you see this screen? If you are trying to edit an existing table, and you see this instead of the table, you probably changed the structure of the source file (if you added a new column, deleted a column, renamed or reordered columns in the source file, the wpDataTable generated from that file will break).

If you're not able to add a new table from an existing data source, please provide me a temporary WP-admin login for your site where this happens, so we could log in and take a look ‘from the inside’ as that’s the most efficient way to see and resolve the issue. We do not interfere with any data or anything else except for the plugin (in case that’s a production version of the site), and of course we do not provide login data to third party. 

You can write credentials here just check Private Reply so nobody can see them except us.

Thanks, that worked.

So, the drop-down doesn't actually work, I did not understand it like this.

This is a bootstrap.js conflict with some other plugin or the theme you're using.

I disabled using bootstrap on back-end:

Now it's working fine.

You're welcome, Denorme

If you have any further questions or issues, please feel free to open a new ticket, and we'll gladly help.