ServerBrief

Learning path

Fix a broken site

When a site stops working, read what it is telling you, then follow the fix for that message. Start here, even in a hurry.

Technician kneeling at a server rack with a laptop

Almost every outage announces its cause somewhere. These steps find it fastest.

  1. Read the error log The single most useful habit, and the fix for most 500 errors.
  2. Gateway errors: 502 The web server is fine; the program behind it is not.
  3. Gateway errors: 504 The program behind it is too slow.
  4. Domain not found DNS is not returning an address.
  5. Certificate warnings HTTPS has expired or does not match.
  6. Redirect loops Two rules sending visitors back and forth.

Not listed here? The full list of error fixes covers every error we have written about.