I am having problems with a script I wrote

If a script you wrote or installed is not working on your hosting account, this guide walks you through the most common causes and how to fix them. These steps apply to PHP, Perl, Python, and other server-side scripts on Ultra Web Hosting.

01. Check Your Error Logs

Your hosting account has two error logs you should check:

• cPanel Error Log - go to cPanel > Metrics > Errors. Shows the most recent PHP, Perl, and CGI errors
• Raw error_log file - PHP errors are also written to an error_log file in the same directory as your script. Check via File Manager or FTP

If errors are not appearing, you may need to enable error logging. Add this to the top of your PHP script for debugging:

ini_set('display_errors', 1);
ini_set('log_errors', 1);
error_reporting(E_ALL);

02. File Permissions

Incorrect permissions are one of the most common causes of script failures:

• PHP files: 644 (owner read/write, group and world read)
• Directories: 755 (owner full, group and world read/execute)
• CGI/Perl scripts: 755 (must be executable)
• Configuration files with passwords: 600 or 640 (restrict access)

03. PHP Version Compatibility

If your script was written for an older PHP version, it may fail on newer versions due to removed functions or changed behavior. Common issues:

• mysql_* functions (e.g., mysql_connect) were removed in PHP 7.0. Use mysqli_* or PDO instead
• each() function was removed in PHP 8.0
• Implicit nullable parameters cause deprecation warnings in PHP 8.4+
• Short open tags (<? without php) may be disabled

You can change your PHP version in cPanel. See How to Change Your PHP Version.

04. File Paths and Includes

Hardcoded paths from another server will not work here. Common path issues:

• Document root: /home/username/public_html/
• Use absolute paths in includes: include('/home/username/public_html/config.php');
• Or use relative paths with __DIR__: include(__DIR__ . '/config.php');

For the full list of server paths, see Server Paths - PHP, Perl, Python, and More.

05. Common Script Errors

• 500 Internal Server Error - syntax error, wrong permissions, or .htaccess conflict. See Error 500 guide
• 403 Forbidden - wrong permissions or mod_security blocking. See 403 error guide
• Blank white page - PHP fatal error with display_errors turned off. Check the error log
• "Class not found" or "Function undefined" - missing PHP extension. Check which extensions are enabled in cPanel > Select PHP Version
• open_basedir restriction - your script is trying to read files outside your home directory. See open_basedir fix
• Form not sending email - see Why Does My Form Not Send Email

06. Shared Hosting Restrictions

Shared hosting has certain restrictions to protect all users on the server:

• exec(), system(), passthru() are disabled. See disabled functions guide
• Memory limit: 384MB per PHP process
• Max execution time: 120 seconds default
• File upload size: configurable via PHP Selector or .htaccess
• No root access - you cannot install system packages or modify server configuration

If your script needs more resources, consider upgrading to a VPS or dedicated server.

Quick Recap: Script Troubleshooting

1. Check the error log in cPanel > Metrics > Errors first
2. Verify permissions are 644 for files, 755 for directories
3. Check PHP version compatibility in cPanel > Select PHP Version
4. Fix file paths to match your hosting account structure
5. Review restrictions if your script needs functions not available on shared hosting

11,872 users found this article useful · Last updated March 2026 · Browse all PHP/MySQL articles