Thanks for updating the thread.
I checked the website and can see you are using X Theme and Cornerstone which are quite old version too. Further checking the licence, I can see that you have only Cornerstone licence and same can't be used to validate X Theme. So, I suggest you to either buy a X Theme licence, should you wish to use X Theme along with Cornerstone. If you want to use only Cornerstone, then please remove X Theme as active theme and then validate Cornerstone.
Before validating Cornerstone, please make sure to update Cornerstone to the latest version as I see that you are using Cornerstone version 2.1.7. After updating, I suggest you to validate Cornerstone. Here's some resources that you can take a look.