This error hides a more specific one behind an extra click. Before trying any fix, get the real error code — it changes what you should do next entirely.
01Reveal the specific error code
Click "Advanced" on the error page. Chrome and Edge show a short code like NET::ERR_CERT_DATE_INVALID or NET::ERR_CERT_COMMON_NAME_INVALID. This tells you exactly what's wrong instead of guessing.
| Code | Meaning | Who can fix it |
|---|---|---|
| ERR_CERT_DATE_INVALID | Certificate expired, or your system clock is wrong | You (clock) or site owner (cert) |
| ERR_CERT_COMMON_NAME_INVALID | Certificate doesn't match the domain you typed | Site owner |
| ERR_CERT_AUTHORITY_INVALID | Certificate wasn't issued by a trusted authority (often self-signed) | Site owner, or expected if it's your own internal server |
| ERR_SSL_VERSION_OR_CIPHER_MISMATCH | Server only supports an outdated TLS version | Site owner |
02If it's ERR_CERT_DATE_INVALID, check your clock first
This is the one case that's frequently your fault, not the site's. Confirm your system date, time, and timezone are correct and set to update automatically, then reload. See the "system clock" steps in our SSL protocol error guide for exact menu paths.
03If it's COMMON_NAME_INVALID or AUTHORITY_INVALID
These mean the certificate itself doesn't match or isn't trusted — this is not something to work around by clicking "proceed anyway" on a site handling anything sensitive (banking, login credentials, payment details). For a low-stakes internal tool or home server you manage yourself, self-signed certificates are expected and proceeding is reasonable. For anything else, treat it as a real warning and don't enter data on the site until it's fixed.
04Test from a different network
If you're on office, school, or hotel Wi-Fi, some networks intercept HTTPS traffic for content filtering using their own certificate, which browsers correctly flag as untrusted. Try the same site on mobile data. If it works there, the certificate itself is fine — the issue is network-level interception, and there's no user-side fix beyond using a different network.
--ignore-certificate-errors as a permanent habit. These remove protection from every site, not just the one giving you trouble.