There are actually many reasons why this could be happening, some of which could be entirely unrelated to your certificate. So, unfortunately, we can’t give specific advice. But, we would recommend clicking on the “Details” button to get more specific information about this error from the browser.
Related posts:
Why does the website say the name on the security certificate does not match the name of the site?
How do I generate a Code Signing certificate? Do I need a CSR?
Why can’t I download my code signing certificate?
I purchased a renewal certificate, but my website still displays the old certificate. What should I do?
