Besides that, if you found a blank page while editing the file, try to display error by editing the main.inc.php file:
Find this code
#Don't display errors
ini_set('display_errors',0);
ini_set('display_startup_errors',0);
Replace with:
#Display errors
ini_set('display_errors',1);
ini_set('display_startup_errors',1);
then save this file.
Hope this helps.
Sincerely,
Masino Sinaga