When a page fails, the server sends a three-digit status code that tells you where to look. Codes starting with 4 mean the request was refused or pointed at something missing; codes starting with 5 mean the server or the application behind it failed. This guide gives you the meaning and the first fix for each one.
Before you start
- Note the exact code and the URL. Check whether every page fails or only one.
- Access to cPanel (open it in one click from Services in your MdmHost dashboard) or SSH for a VPS.
- Know where the logs are: cPanel error log and raw access logs.
Quick reference
| Code | Meaning | Most common cause | First check |
|---|---|---|---|
| 403 Forbidden | Server refuses access | Wrong file permissions, a Deny rule in .htaccess, missing index file, firewall block | Folders 755, files 644, review .htaccess |
| 404 Not Found | Nothing at that URL | File deleted or renamed, wrong document root, broken permalinks | File Manager path; re-save WordPress permalinks |
| 500 Internal Server Error | Application or config crashed | .htaccess syntax error, PHP fatal error, wrong PHP version | Error log; rename .htaccess to test |
| 502 Bad Gateway | Proxy got no valid reply from the backend | PHP-FPM, Node or app container stopped or crashed | Restart the backend; check its logs |
| 503 Service Unavailable | Server temporarily cannot handle the request | Resource limit reached, maintenance mode, backend overloaded | Resource usage; stuck .maintenance file |
| 504 Gateway Timeout | Backend answered too slowly | Slow database queries, long PHP scripts, external API timeouts | Slow logs; raise timeouts only after fixing the slowness |
403 Forbidden
- In cPanel → Files → File Manager, check permissions: folders
755, files644, and never777. - Make sure the folder has an
index.phporindex.html. - Look for
Deny fromorRequire all deniedlines in.htaccess. - If only you see it, your IP may be blocked by the firewall; check with our IP checker and open a ticket.
Full walkthrough: Fix 403 Forbidden on cPanel.
404 Not Found
Confirm the file exists in the right folder (the addon domain's document root, not always public_html). On WordPress, go to Settings → Permalinks and click Save Changes. Details: Fix 404 Not Found.
500 Internal Server Error
Open cPanel → Metrics → Errors or the error_log file in the site folder; the last line usually names the problem. Temporarily rename .htaccess to .htaccess.bak; if the site comes back, the error is in that file. See Fix 500 Internal Server Error and, for WordPress, WordPress 500 error.
502 Bad Gateway and 504 Gateway Timeout
Both come from a proxy (LiteSpeed, Nginx, Cloudflare) talking to something behind it. A 502 means the backend is down or crashed; a 504 means it was too slow. On a VPS, check the service with systemctl status php8.3-fpm or docker ps. See Fix 502 Bad Gateway and Fix 504 Gateway Timeout.
503 Service Unavailable
- Resource limits: on CloudLinux hosting, hitting the entry-process or CPU limit returns 503 or 508. Check cPanel → Metrics → Resource Usage and read 508 Resource Limit Reached.
- Stuck maintenance mode: WordPress leaves a
.maintenancefile in the site root if an update is interrupted. Delete it. - Traffic spikes or bots: check the raw access log for one IP or URL hammering the site, and enable caching with LiteSpeed Cache.
- VPS: the web server or PHP-FPM pool has no free workers. See PHP-FPM pool tuning.
Tip: If you use Cloudflare and see a Cloudflare-branded 52x page, the problem is between Cloudflare and your server. Test the site directly by temporarily pausing Cloudflare.
Still stuck?
Open a ticket at /tickets/new with the URL, the error code, the time it happened and what you already tried. MdmHost support is available 24/7.