Im still getting the "Your site can't communicate with hidden link. Code 403" response, while trying to register the domain with site key.
Already tried re-register the domain, turn off all the plugins and still the same problem. When i check Installer system status on already registered pages on our server, the status is "all green", but when i try to register new one, we still get "Unable to parse data from service response." response. Is there possibility, you can check if there is something blocking or give some more advice please?
I understand the issue you're having and will try my best to assist you in this matter.
This issue most of the time happens if the Firewall on your site or server blocks access to essential endpoints. Please follow the instructions mentioned in the link below and check if that helps to solve the issue.