Firefox: "This Connection is Untrusted" after update

Hello, as the title says I’ve been receiving this warning in any site I visit - including https addresses - after I updated Avast; I had then to disable the Web Shield.
Is there an option to import Avast’s certificate to Firefox as it is done in Thunderbird? Clearly any solution will do.

Thanks

Hello,
Importing certificate to Firefox is similar to Thunderbird:
http://www.avast.com/faq.php?article=AVKB91#artTitle
Avast uses the same root certificate for Mail and Web Shields.

I have the same problem. Even google.com is untrusted. I tried your link but the instructions don’t apply. When I go to Active protection, I don’t have a gear to click. I have a customize button. When I click on it, I don’t find any reference to “SSL scanning”.

I had this issue before, disabling HTTPS Scanning seems to work.

I don’t know how it can be triggered but now I don’t need to change or disabled anything on avast settings. Everything is set to default now.