@gianlucagiardina2
In first post you told that you had problems on Windows - now you say that on Windows all worked well.
On Ubuntu I have no experience at all, sorry. Do other Ubuntu browsers see and use your CA there?
Hello. Nice to meet you. It worked. Thank you. I was not sure if addon extensions from Google [Chrome] worked in Opera. I see they do! I see Checker Plus for Gmail and Gmail Checker Lite also work as well.