21. Feb 2026
1 min
When your website shows an error, the HTTP status code helps you diagnose it:
403 – Forbidden (access denied):
The server refuses access. Common causes:
• Wrong file permissions (folders: 755, files: 644)
• Missing index.html or index.php
• Blocked by .htaccess rules
Solution: Check the permissions in the Plesk File Manager.
500 – Internal Server Error:
A generic server error. Common causes:
• An error in the .htaccess file
• PHP errors in your code
• PHP memory limit exhausted
Solution: Check the error logs in Plesk under "Logs".
503 – Service Unavailable:
The server is temporarily overloaded. Common causes:
• Too many simultaneous requests
• All PHP workers busy
• Maintenance work
Solution: Wait a few minutes or optimize your website's performance.