hello IgoRock, you can try this in order to restore the default set of certificates used in firefox: go to firefox > help > troubleshooting information, click on profile folder/show folder and close all firefox windows afterwards. a windows explorer window should open up - in there rename the file named cert8.db into something like oldcert8.db - it will be regenerated again the next time you launch the browser.

That is an intermediate certificate and needs to be send by the web server.

You can inspect the certificate chain via a site like this:

• http://www.networking4all.com/en/support/tools/site+check/

That is probably the second certificate on this page:

RSA Secondary EV SSL Intermediate CA Certificate:

• https://knowledge.verisign.com/support/ssl-certificates-support/index?page=content&id=AR1728