How to Fix: Certificate error with Internet Explorer 9

One of your coworkers has installed Internet Explorer 9 on their computer, but now they're experiencing trouble accessing certain websites that were previously accessible in other browsers. The issue is specific to this particular website (https://secure.projectmanager.com/login.aspx), where IE9 displays a 'Certificate Error: Navigation Blocked' message. Despite clicking the 'Continue to site' button, nothing changes, and the page remains stuck.

This error can be frustrating for your coworker, especially since they're unable to access the website in other browsers (Firefox and Chrome) or even in Internet Explorer 8 on a different computer. The fact that this is not a cache issue, as the site works fine in these other browsers and on your own computer, makes it more complex to diagnose.

⚠️ Common Causes

• The primary reason for this error is an issue with the website's SSL certificate or the way it's being handled by Internet Explorer 9. When a website uses a non-standard or incorrectly configured SSL certificate, IE9 may block access due to security concerns.
• Another possible cause could be a misconfigured Windows Firewall setting or a software conflict that's preventing IE9 from communicating with the website's server.

🛠️ Step-by-Step Verified Fixes

🎯 Final Words

To resolve this issue, you can try enabling the Developer Tools in IE9 to inspect the SSL certificate details, or configure the browser to trust the website's certificate by adding it to the Trusted Sites list. If these steps don't work, further troubleshooting may be necessary to identify and address any underlying software conflicts or Windows Firewall settings.