Thank you for writing in, can you confirm that you installed and activate both X and Cornerstone?
Also, please confirm that you are fully updated? (Theme and Cornerstone)
You can find the latest version numbers here, Then you can compare them to what's installed on your site.
If you find anything to be out of date, you can review our update guide.
If you can confirm that, please follow the article below on how you can set up a demo.
Setup - Demo Content
Hope it helps,