During debugging, error messages come in very handy. A quick way to debug errors on a PHP based site is to enable error display for a short while.
To do this on a website that is on CWP, use the following guide:
1.Login to your CWP user panel. The link to do this is https://YOUR_VPS_IP:2083
2.Navigate to File Manager under File Management section
3.A new tab will be opened. Click on the public_html folder (or the respective root folder of your site if you are using a subdomain or addon.)
4.Look for two files, php.ini and .user.ini
We need to open both files, one at a time, and edit them, changing display_errors = Off to display_errors = On. Click Save at the top right.
5. On accessing the site now, you should see your php errors display.
Note: Once done debugging and fixing the error, please turn Off the error display. It is not good for live websites to have that since visitors will be shown the errors.