How do I get rid of this message?

Hi, ALL,
I'm using FF as my default browser and I have Avira as my antivirus.
Recently Avira got updated and I was stupid enough to turn on the internal Avira protection on FF.
Now, when I start FF, I see a little green window on top of the page and if I click on it, it becomes fully visible.

So everything is good, but...
Every time I'm opening the page (which by itself takes a lot of time), I see a following warning:

The message could've probably be OK, but along with the message the current FF tab changes to another one.

So, it's not just dismissing the dialog with "Continue" as it comes from Avira, but also changing the tab back to the one I was - which by that time already becomes loaded/updated.

All this makes FF completely unusable.

Now in FF I have 2 plug-ins installed: NoScript and AdBlock.
So maybe it is a conflict between NoScript and Avira?

Or maybe I got hijacked and its not Avira at all?

Thank you for any hints with fighting the issue.

I'm going to try and attach a screenshot so that you better understand of what I'm talking about. The green window is right under the "Address Bar" and it is visible only the bottom of it. When you click it, it slides down. And there is the message I would like to get rid of.

 

OK, will post there.
The problem is that this dialog shows up every time the page is loaded/refreshed. And I don't think it should do something like this too often.
Hence the posting here in this forum.
Also, just in case I started MalwareBytes scan.

Thank you.