This means that URL in the browser and the common name in the certificate are not an EXACT match (for instance, the www. is missing). Another common reason for this is the web host’s certificate is incorrectly assigned to your domain name. Or, you purchased a certificate that does not cover the specific subdomain you are looking at.
Related posts:
My certificate works in my browser, but my visitors get a Security Alert that says ‘The security certificate was issued by a company you have not chosen to trust…’ What is the problem?
I purchased a renewal certificate, but my website still displays the old certificate. What should I do?
What is a Multi-domain or SAN certificate?
How many domains can I secure with a Multi-Domain SSL Certificate?
