An HTTP error code identifies the stage at which a request fails; it does not automatically reveal the cause. Establish the error type first, then review logs, recent changes and server load. This prevents random troubleshooting and unnecessary damage.
403: access forbidden
The server understands the request but refuses it. Possible causes include permissions, security rules, an IP block, a missing index or a web application firewall. Do not disable protection blindly; find the precise rule and request in the logs.
404: the requested page was not found
An occasional 404 after a typing error is normal. Many new 404s after a change commonly indicate permalinks, redirects, removed content or an incorrect document root. Add relevant 301 redirects, but do not send every missing URL to the homepage.
500: internal server error
A 500 is a general response. Common causes include a PHP exception, broken plugin, invalid .htaccess rule, missing extension or incorrect permissions. Review the error log at the exact time and carefully reverse the most recent change.
503: temporarily unavailable
A 503 may be intentional during maintenance, or indicate exhausted workers, overload or an unavailable backend. Check whether every page is affected or only dynamic requests, and whether traffic or scheduled tasks recently increased.
508: resource limit reached
In shared hosting, 508 often means a process or entry-process limit was reached. The real cause may be traffic, hostile bots, a slow query, a heavy plugin or insufficient plan capacity. Extra resources are sustainable only when the underlying workload is understood. See our guide to CPU, RAM, I/O and processes.
Safe diagnostic plan
- Record the URL, time, code and reproduction steps.
- Check status information, DNS and the certificate.
- Review web server, PHP, application and security logs.
- Compare the incident with deployments and configuration changes.
- Test one hypothesis at a time and record changes.
- After recovery, test forms, mail, cache and background jobs.
Frequently asked questions
Must WordPress be reinstalled after a 500?
Usually not. First locate the specific PHP or server error and the relevant recent change.
Is a 404 bad for SEO?
Normal 404s are not automatically harmful. Repair important broken links and redirect only when a genuine replacement exists.
Why does an error disappear by itself?
Temporary load, caching, rate limits or a restart may hide the symptom. Review the logs anyway to prevent recurrence.
When opening a ticket, include the URL, time, error code and a screenshot through the Gigatech support portal.
