Hi There @odsadmin
Thanks for writing in! The latest X theme (v6.1.6) is now supports WooCommerce (v3.4.2). Also make sure that you’re using the latest Cornerstone plugin as well (v3.1.6). You can see all the X compatible version numbers from here (https://theme.co/apex/forum/t/troubleshooting-version-compatibility/195).
First of all, take a full backup of your current site and update to the latest X compatible versions accordingly.
If you’re still having issues, check your PHP version and make sure that you’re using PHP v5.6.x or later to avoid further incompatibility issues.
Also you will need to disable your 3rd party plugins and test for a plugin conflict as well. Make sure to purge your server cache, if you’re using a caching plugin on your server before testing.
Let us know how it goes.
Thanks!