What is your anti-virus/security software?

My anti-virus is AVG Internet Security, paid for. The point is that the last two updated DID install, but I still get this repeated notification pane (not a Windows notification).

One other thing I found is that clicking on 'Learn more' in the pane opens the web page in Thunderbird, not Firefox, and of course that doesn't work properly; one can only read the text, nothing more.

See https://support.mozilla.org/en-US/questions/1384853#answer-1525849 Avast is essentially the same as AVG.

I've created the exceptions, but of course I don't know yest whether the notifications will stop until another update is released.