The number one cause is a wrong date and time on your device (Solution 1) - the browser compares your clock against the site's certificate validity and refuses the connection when they do not match. The second step is finding out whether the error happens on one site or on all of them: on one site the problem is usually the site's; on all of them it is your device, your network or your antivirus. Never type a password or card details on a page that showed this warning.
What causes this problem
- A wrong date, time or time zone on the device - the certificate looks expired or not yet valid.
- The site's certificate genuinely expired, or was issued for a different address.
- A public Wi-Fi network with a sign-in page (airport, hotel, café) intercepting the connection before you log in.
- Antivirus or firewall software with HTTPS inspection enabled, placing itself in the middle of the connection.
- A browser extension interfering with traffic, especially proxies and aggressive blockers.
- An old certificate cached in the browser after the site renewed its own.
- Note the code under the message: ERR_CERT_DATE_INVALID points to the clock or an expired certificate; ERR_CERT_AUTHORITY_INVALID to antivirus or network inspection; ERR_CERT_COMMON_NAME_INVALID to a certificate issued for another address.
- Try two or three large, well-known sites. If only one fails, the problem is probably theirs; if all fail, it is on your side.
- If you can, test on your phone's mobile data - that instantly separates a network problem from a device problem.
- While the warning is showing, do not type passwords, banking details or card numbers on that page.
Solutions, in the order to try them
1Fix the date, time and time zone
Every certificate has a start date and an expiry date. If your device's clock falls outside that window, the browser concludes the certificate is invalid - even when everything is fine on the site's end. This is the most common cause, and the easiest to fix.
- Windows: Settings > Time and language > Date and time. Turn on Set time automatically and click Sync now.
- Android: Settings > System > Date and time, with the automatic options enabled.
- iPhone: Settings > General > Date and Time and turn on Set Automatically.
- Check the time zone as well, not just the time - a wrong zone shifts the date in some cases.
- Reload the page after syncing.
2Test in an incognito window and in another browser
This test separates, in a minute, what belongs to your Chrome profile (an extension, the cache, a stored certificate) from what belongs to the site or the network.
- Open an incognito window with Ctrl + Shift + N (Cmd + Shift + N on Mac) and visit the same address.
- If it works in incognito, the cause is an extension or your profile cache - go to Solutions 4 and 5.
- If it fails there too, try another browser you have installed.
- If it fails in every browser, the problem is the device, the network or the site - not Chrome.
3Sign in to the public Wi-Fi portal
Hotel, airport and café networks intercept the first connection to show their sign-in page. Because that interception is technically identical to an attack, the browser warns you - and the warning disappears as soon as you authenticate.
- Disconnect and reconnect to the Wi-Fi network to force the sign-in page to appear.
- If it does not open by itself, visit a plain non-HTTPS address such as neverssl.com, which forces the portal to show up.
- Complete the network's sign-in, and only then go back to the site you wanted.
4Clear the SSL cache and browsing data
When a site renews its certificate, the browser or the system may keep presenting the old one for a while. Clearing that cache resolves the mismatch.
- In Chrome, open Settings > Privacy and security > Delete browsing data.
- Choose the All time range and tick Cached images and files and Cookies.
- On Windows, also clear the system SSL cache: Control Panel > Internet Options > Content tab > Clear SSL state.
- Close the browser completely and open it again.
5Temporarily turn off your antivirus's HTTPS inspection
Several antivirus products open the secure connection to inspect its contents and close it again with a certificate of their own. When that mechanism misfires, the browser reports an invalid authority on every site at once.
- Open your antivirus settings and look for HTTPS scanning, Web protection or SSL scanning.
- Turn off only that feature - not the whole antivirus - and reload the site.
- If the error disappears, update the antivirus to its latest version before switching the feature back on.
- If you use a VPN, test with it disconnected as well.
6Check whether it is the site's certificate that expired
If you got this far and the error happens on a single site, there is probably nothing to fix on your side - and the site owner needs to renew their certificate.
- Click Not secure in the address bar and open the certificate details.
- Look at the validity dates and the address it was issued to.
- If it is expired, or issued for a different domain, the problem is the site's.
- In that case, let the site owner know and wait - do not bypass the warning to keep using it.
Applies to
| System | Status |
|---|---|
| Chrome on Windows, macOS and Android | Confirmed |
| Microsoft Edge | Confirmed |
| Firefox and Safari | The message is worded differently, but the causes and fixes are identical |
Menu names can change slightly between versions. If a step above does not match what you see on screen, the official support page from the manufacturer has the most current wording for your version.
Frequently asked questions
Last checked: Sep 19, 2026 · We review this guide whenever the manufacturer changes the process.