Resolve PHP MySQL Syntax Issues

I’m maintaining a legacy PHP site and my error logs are filling up with syntax-related messages as well as deprecation notices. So far I’ve been tracking everything purely through the log files—no on-screen errors are shown to end-users—and the biggest offenders seem to be functions that are no longer supported in recent PHP versions.

Here’s what I need from you: locate the exact syntax mistakes the logs point to, correct them, and swap out the deprecated functions for safe, modern equivalents. Please test every fix against the current MySQL database to be sure no query breaks slip through; the project uses plain PHP without any framework layers, so you’ll be working directly in the .php files.

Deliverables
• Clean, warning-free code (no parse, syntax, or deprecation errors in the logs)
• A brief change log listing each file you touched and the reason for the edit

You’re free to fire up a debugger or any tooling you like, as long as the final result is a silent error log and a fully functioning site.
This is in my php error logs
PHP Fatal error: require_once(): Failed opening required '/home/moto/public_html/Settings.php' (include_path='.:/opt/cpanel/ea-php74/root/usr/share/pear') in /home/moto/public_html/index.php on line 48