Website errors can break traffic, rankings, sales, and user trust. Some stop visitors from opening the site. Others block logins, break HTTPS, or make WordPress unusable.
This guide brings the most important website errors into one place. Use it to identify the problem fast, understand what it means, and open the right step-by-step fix.
Quick Navigation
How to Identify Your Error Fast
Most website errors fall into four groups:
- DNS errors — the domain cannot be found or resolved.
- SSL errors — the secure HTTPS connection fails.
- Server errors — the server is reachable but returns a failure.
- WordPress errors — the CMS or PHP layer breaks the site.
Use this simple logic:
- If the browser says the site cannot be found, start with DNS.
- If the browser warns about certificates or secure connection problems, start with SSL.
- If you see codes like 500, 502, 503, or 504, start with Server Errors.
- If the site is WordPress and shows a blank page, critical error, or plugin issue, start with WordPress Errors.
DNS Errors
DNS errors happen before the browser reaches the website server. If DNS fails, the domain name cannot be translated into an IP address.
Most Common DNS Errors
- DNS_PROBE_FINISHED_NXDOMAIN — the domain does not resolve.
- DNS Server Not Responding — your device cannot get a reply from DNS.
- ERR_NAME_NOT_RESOLVED — the browser cannot resolve the website name.
- Domain Not Pointing to Hosting — DNS records do not point to the correct server.
- DNS Propagation — How Long It Takes and How to Fix It — DNS changes are not visible everywhere yet.
Typical DNS Symptoms
- The site cannot be found
- The domain opens the wrong website
- One network works, another does not
- The site broke after changing nameservers or A records
Fast DNS Checklist
- Check nameservers
- Verify A record points to the correct IP
- Flush local DNS cache
- Try Google DNS or Cloudflare DNS
- Wait for propagation if records were just changed
SSL & HTTPS Errors
SSL errors happen when the browser or proxy cannot establish a trusted secure connection. These issues are common after certificate renewals, migrations, CDN changes, or forced HTTPS redirects.
Most Common SSL Errors
- Error 525 SSL Handshake Failed — the secure handshake fails between CDN and origin.
- Error 526 Invalid SSL Certificate — strict SSL validation rejects the origin certificate.
- ERR_SSL_PROTOCOL_ERROR — the browser cannot establish a secure HTTPS session.
- SSL Handshake Failed — the TLS negotiation fails before content loads.
- Mixed Content Error — HTTPS pages load HTTP resources.
- NET::ERR_CERT_AUTHORITY_INVALID — the browser does not trust the certificate authority.
- SSL Certificate Not Trusted — the certificate cannot be verified.
- Too Many Redirects After SSL — HTTPS causes a redirect loop.
Typical SSL Symptoms
- “This site cannot provide a secure connection”
- Browser certificate warnings
- HTTPS works on one device but not another
- Cloudflare SSL pages show 525 or 526
- Site breaks after forcing HTTPS
Fast SSL Checklist
- Check that the certificate is valid and not expired
- Install the full certificate chain
- Confirm the certificate matches the domain
- Verify TLS 1.2 or 1.3 support
- Make sure CDN SSL mode matches the origin setup
Server Errors
Server errors happen after the request reaches the server. The domain works, but the application, proxy, or backend service fails to return a valid response.
Most Common Server Errors
- 500 Internal Server Error — the server failed while processing the request.
- 502 Bad Gateway — one server received an invalid response from another.
- 503 Service Unavailable — the server is running but cannot handle requests right now.
- 504 Gateway Timeout — the upstream response took too long.
- Upstream Timeout Error — a proxy or gateway waited too long for the backend.
Cloudflare & Proxy-Related Errors
- Error 520 Unknown Error
- Error 521 Web Server Is Down
- Error 522 Connection Timed Out
- Error 523 Origin Is Unreachable
- Error 524 Timeout Occurred
- Cloudflare Error 1020 Access Denied
Typical Server Error Symptoms
- The site was working, then suddenly stopped
- Only some pages fail
- The admin area works, but the public site does not
- Traffic spikes trigger outages
- Reverse proxy or CDN is in front of the site
Fast Server Checklist
- Check CPU, RAM, and worker limits
- Review error logs
- Restart web and application services
- Inspect backend service health
- Check timeout and proxy settings
WordPress Errors
WordPress errors usually come from plugins, themes, PHP memory limits, database issues, or failed updates. These are some of the most common and highest-intent problems site owners search for.
Most Common WordPress Errors
- Error Establishing Database Connection
- White Screen of Death
- 403 Forbidden WordPress
- Memory Exhausted Error
- Critical Error on This Website
- Destination Folder Already Exists
Typical WordPress Symptoms
- Blank page after updating a plugin
- WordPress admin inaccessible
- Fatal PHP error after theme edit
- Database message instead of homepage
- Install/update failure in plugins or themes
Fast WordPress Checklist
- Disable recent plugins
- Switch to a default theme
- Enable debug mode
- Check wp-config.php settings
- Increase PHP memory limit
- Inspect server logs
What to Check First Based on the Error
| Error Type | Most Likely Cause | First Thing to Check |
|---|---|---|
| DNS_PROBE_FINISHED_NXDOMAIN | DNS records or nameservers | A record, nameservers, propagation |
| ERR_SSL_PROTOCOL_ERROR | Broken HTTPS configuration | Certificate, TLS version, redirects |
| 500 Internal Server Error | Application or config failure | Logs, plugins, .htaccess |
| 502 Bad Gateway | Proxy/upstream failure | Backend service health |
| 503 Service Unavailable | Overload or maintenance mode | CPU, RAM, maintenance flags |
| 504 Gateway Timeout | Backend too slow | Slow queries, timeout settings |
| Error Establishing Database Connection | DB credentials or DB server failure | wp-config.php, MySQL status |
| White Screen of Death | Plugin, theme, or memory failure | Disable plugins, enable debug |
When the Problem Is Probably Your Hosting
Some website errors are not just configuration mistakes. They happen because the hosting environment is too weak, unstable, or badly configured.
That is especially common with:
- Repeated 502, 503, and 504 errors
- Frequent PHP memory exhaustion
- Slow database response under normal traffic
- SSL and DNS issues after migrations
If the same problems return again and again, the issue may not be a plugin or a single setting. The real bottleneck may be the hosting stack.
This is the safest place to add a hosting comparison or affiliate recommendation later. Keep it technical and useful, not aggressive.
How These Errors Affect SEO
Website errors can hurt SEO in different ways:
- DNS errors prevent Google from reaching the site at all.
- SSL errors block secure crawling and reduce trust.
- Server errors reduce crawl frequency.
- WordPress errors can make important pages unavailable.
Short issues usually do not destroy rankings. Repeated or long-running problems do.
The faster you fix the issue, the lower the SEO damage.
Best Next Step If You Are Troubleshooting Right Now
If you are in the middle of a live issue, use this order:
- Identify the error group: DNS, SSL, Server, or WordPress.
- Open the most relevant guide from this page.
- Apply the Quick Fix first.
- Check logs before making random changes.
- Test after each change, not after ten changes at once.
This saves time and prevents new problems.
Related Error Collections
Replace or add these collection pages when you publish them.
Final Summary
Website errors are easier to fix when you classify them correctly. DNS errors stop domain resolution. SSL errors break secure connections. Server errors interrupt request processing. WordPress errors usually come from plugins, themes, memory limits, or database failures.
Use this page as your master directory. Open the matching guide, follow the troubleshooting steps, and fix the issue at the correct layer instead of guessing.