Hi there,
Thanks for the details.
I was able to login and check your site and Cornerstone does not load because there are some Javascript errors that is stopping it from loading.
You seem to be using an incompatible version of X and Cornerstone which might be the root cause of the issue. You have updated Cornerstone to the latest version but left X not updated. Kindly make sure that you update X to the latest version the clear the site’s cache after updating.
In case the issue persists, please try testing for a plugin conflict. You can do this by deactivating all third party plugins, and seeing if the problem remains. If it’s fixed, you’ll know a plugin caused the problem, and you can narrow down which one by reactivating them one at a time.
Let us know how it goes.