We have tested every forum solution listed and are still at a loss - We are receiving this error each time we try to select “Edit with Cornerstone” within our pages that we’ve created within WordPress.
Here’s are some of the solutions that we have tried thus far:
-Enable the WordPress debug mode. You might be able to see an error message on the site right away. If not, the error log could reveal where the problem is originating.
-If you’re using a child theme, try switching to the parent theme to see if that makes a difference. The conflict could be in your customizations.
-Test for a plugin conflict by disabling all third party plugins except the Cornerstone plugin if you use X. IF the problem is fixed, activate the plugins one by one to find the plugin responsible for the problem.
-Make sure that you use PHP version 5.6.x or 7.1.x or 7.2.x. Contact your hosting service provider to make sure that you do not have an old version of the PHP.
-Make sure that you increase the PHP memory limit to at least 512M. Follow the steps mentioned here for more information.
-Testing For Theme Related Issue
-Testing For Plugin Conflict
-Theme Update
-Child Theme
-Css/Js Customization
-Increasing Php Memory Limit
-Disabling Cache
-Disabling Cdn
-Permalinks
-Version Compatibility
Any insight is welcome.
Thanks!

