The error text in Chrome explicitly states that your connection is not private. Let’s have a look at a few of the variations. Your operating system will also affect the exact message you see. While you’ll typically encounter the NET::ERR_CERT_DATE_INVALID error message when using Chrome, other browsers have their own version of the error. Seeing this error may also raise questions about whether your site is secure. Regardless of the reason for the error, you’ll want to fix it quickly, as it can affect traffic. In the case of this particular error, the certificate has expired. There might be a problem with the certificate itself.This could be due to a setting, or the platform could be incompatible with the SSL certificate being used. The browser that is accessing the site is the problem.This could include a setting on their computer, antivirus software, or the internet connection. There’s a problem with the user’s computer.There are a few main reasons you may see this error: While the NET::ERR_CERT_DATE_INVALID error is not unusual and can be easily fixed, it can sometimes indicate a legitimate threat. You can ignore it and click through to the page you’re trying to visit, but we don’t recommend it. In most cases, the error won’t actually prevent you from accessing the site. The most common browser to find this error on is Google Chrome, but there are variations on other browsers as well: The NET::ERR_CERT_DATE_INVALID error message in Firefox. The NET::ERR_CERT_DATE_INVALID error is often referred to as ‘ your connection is not private,’ as this is the message you’ll frequently receive when you encounter it. What’s the NET::ERR_CERT_DATE_INVALID Error?

Firefox 3.6.28 invalid certificate