In short: A 403 response means access was refused, a 404 means the requested path was not found, and a 500 means the server or application failed while processing the request. The status code narrows the search, but the logs usually contain the useful explanation.
| Code | Meaning | Common causes |
|---|---|---|
| 403 Forbidden | The server understood the request but will not serve it. | Permissions, missing index file, access rule, security rule or blocked address. |
| 404 Not Found | No matching public resource was found. | Wrong URL, moved file, document-root error, broken rewrite or application route. |
| 500 Internal Server Error | The application or server encountered an unexpected failure. | PHP error, incompatible PHP version, bad .htaccess, missing extension, permissions or exhausted resources. |
Start with these checks
- Record the exact URL, status code and time, including the time zone.
- Try a private browser window and one other network to rule out a cached response.
- Check whether the homepage and SiteWorx still open.
- Review the most recent deployment, plugin, theme, PHP, permission and DNS changes.
- In SiteWorx, go to Administration > Logs, choose Web Server Logs, and inspect the relevant error and access log around the recorded time.
For a 403 error
Confirm that the requested file exists beneath the correct domain's document root and that an index file is present. Review .htaccess access rules. Typical website files are readable by the account and directories must be searchable; do not solve the problem by setting everything to 777.
For a 404 error
Check spelling, capitalisation and the configured document root. If a CMS produces the 404, refresh its permalink or routing configuration only after taking a backup. Confirm that rewrite rules were deployed with the application.
For a 500 error
Check the PHP error log first. If the error began after changing PHP, return to the previous version. Temporarily reversing the most recent known change is safer than making several speculative changes at once.
Further reading: InterWorx: View web-server logs and InterWorx: Change file permissions.
If the whole website is unavailable
An HTTP status is only one possible failure. DNS, domain expiry, TLS, suspension and network problems may prevent the server from returning an HTTP response at all. Use My website is down — what should I check? to establish whether one page, one site or several services are affected before changing files or configuration.
