A website request passes through several layers, so the same symptom can have very different causes. Isolate the failing layer before editing the site.
- Browser-only: the site works in another browser or private window. Clear browser cache and test extensions.
- DNS-related: the hostname does not resolve, resolves to an unexpected address, or different resolvers return different answers. Check authoritative nameservers and DNS records.
- Web-server/account: multiple applications on the same account fail, HTTP errors appear in cPanel Errors, or account resource faults coincide with the failure.
- Application-specific: static files load but one application fails, or the error follows a plugin, theme, PHP, or database change.
Use the narrowest reproducible test possible. For example, compare the root domain with a known static file, then compare that result with the application page that fails.
