This issue started with the Elements being “not found” when clicking on the tab.
After following the permalink fixes suggested on the forums now Cornerstone returns “The requested URL /x/ was not found on this server.”
Following the instructions in post https://theme.co/apex/forum/t/cornerstone-unavailable-after-update-the-requested-url-x-was-not-found-on-this-server/1560/6
also did not correct the issue.
.htaccess file is writable and contains
RewriteEngine On
RewriteBase /
RewriteRule ^index.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
Settings > Permalinks > Post_Name
does not fix anything
Please help