Firstly, Koh Lipe is my most favorite island in Thailand!
As for the site issue, did you also update X to the most recent version as it might cause an incompatibility issue if it's either X or Cornerstone is updated. Here is a link for a details information on how to do an update:
Please remember to clear all caches when updating so that the code from the latest release is always in use. This will help you to avoid any potential errors or any unexpected display issue on the site.
If both are updated but you still can't load Cornerstone pages, 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.
In case the issue persists, please provide us with the admin access to your site in a Secure Note: