The specific error being returned from your server is:
Not Acceptable!
An appropriate representation of the requested resource could not be found on this server. This error was generated by Mod_Security.
That means that the mod_security extension (an add-on to Apache) is blocking our automated tool's request to fetch your page. There's nothing we can do on our end to fix the problem as it's the server blocking the request.
With that said, I just looked over the HTML on your page and all the checks that our automated tool looks for would have passed. I'd recommend continuing with the setup process and hopefully you won't run into any issues. If you do run into any functional issues though, just let us know, and we'll gladly help however we can.
Thanks,
Alex