Hello @kvpadmin,
Thanks for updating the thread.
I logged into the backend using the credentials you have shared and can confirm that upon entering the purchase code page is blank (I got the purchase code from your licence page). Upon further checking the dev console, I see multiple error messages. Please see screenshot (please see secure note).
I suggest you to completely delete X Theme and Cornerstone and then download fresh copy of X Theme and install the same and see how it goes.
Thanks.