Several factors could cause this issue. They’re mostly server and WordPress setup related but could be client (browser) side as well like in this thread.
For server setup, please go to X/Pro > Status and quickly check these server setup items as they usually cause issues if not configured correctly or not sufficient.
PHP Version should be 5.6 or above. Check what WordPress recommends at https://wordpress.org/about/requirements/
Memory Limit should be enough to run your WordPress setup, including theme and plugins. 256M of memory usually is sufficient, but if you have lots of plugins, you might need more. Please ask your web host to assist you with this. If you wish to do this yourself, please add this code in your wp-config.php.
define( 'WP_MEMORY_LIMIT', '256M' );
define( 'WP_MAX_MEMORY_LIMIT', '512M' );
Here’s a tutorial video for guidance:
Time Limit. Try 120s or higher of
max_execution_time. Please ask your web host to assist you with this.
Still, server and WordPress related, you might be having problems with WordPress Heartbeat. Below is a link to an article to stop or control WordPress Heartbeat.
Another thing you could check is your WordPress URL setup. Please see this thread https://theme.co/apex/forum/t/cornerstone-spinning-problem/66603/3
If you’ve tried all the suggestions above and nothing helps, please give us the following information in a Secure Note.
- WordPress Login URL
- Admin level username and password
- FTP access