Please help me determine what is causing this accordion issue. Displays ok on front but back end shows this and I typically cannot open have to delete and start over?
I see that you are using X Theme 6.5.5 and Cornerstone 3.5.4. Please update X Theme and Cornerstone to latest version 6.5.6 and 3.5.6 respectively. After updating please clear cache and see if the Invalid template markup error message is still showing up. Here’s resources that you can refer to update:
If you still have problems kindly get back to us with the result of the steps above and URL/User/Pass of your WordPress dashboard using the Secure Note functionality of the post to follow up the case.