Comment out the top line there, and add the rest to your wp-config.php file to get more detailed error reporting from your WordPress site. Definitely don’t do this live, do it for local development and testing.
// define('WP_DEBUG', false);
This code will allow WordPress to start displaying PHP errors, warnings, and notices again.
Finding log files
Now the question is where are the log files?
You can find them in following directories:
1 – Beside “wp-config.php” file there is a file named “error.log” or “debug.log”
2 – In “wp-content” folder there is a file named “debug.log”
3 – In “wp-admin” folder there is a file named “error.log”
You can check those files with any text editor to see what’s the issue on your website.