Hi Augusto,
Thanks for getting in touch.
This error (E1002) happens when the AJAX function for loading in the verification page does not work correctly and fails before being able to get a valid response. This can happen if there is a server issue, a timeout, the URL for the request is wrong, the AJAX is blocked, etc.
I have updated the plugin just now to give additional information when this error occurs. To see this information, depending on your browser, you can use something like DevTools on Chrome to see the console error messages. 3 error messages are created at the same time after the error happens, this information should tell you why the error has happened, and we may be able to find a solution based on this information.
Let me know what you find.