When I want to open the page ‘www.audiosex.pro’ (audiosite) with Mozilla Firefox (version 41.0.2, latest), I get a message from Avast (latest Freeware version) and the page won’t load.
No idea about the main problem but the FireFox tab issue is probably to do with the recent version update where new tabs do not open with your homepage any more (that option has been removed ) or blank unless you change the settings.
New tabs now open with unwanted by many users ‘suggestion’ pane links based on your web site visiting habits. My guess is that one or more of those panes, even the same one, is being similarly blocked and that’s why you get that message.
If you want a new tab to load your homepage then a simple way I was made aware of only a few weeks ago is to move the cursor to the tab bar and use middle mouse click (click down on the mouse wheel).
But to stop the annoying ‘suggestion’ panes in new tabs opened in the normal way unfortunately there’s no FireFox about:config fix you have to install a third party add-on now. I use:-
I have the latest firefox 41.0.2 and I don’t have a home page assigned, so ordinarily I get a blank tab when I start FF on my win7 system.
The only difference I have on this system is that I use the OneTab add-on and have 13 regularly used URLs, etc. and that tab I leave, all others are closed before shutting down FF. I also have it set to open previously open tabs.
There isn’t any problem opening the homepage with the latest version of FF. The change is what happens when you open a new tab. No longer can you set those to open your homepage. The only options now , as I have already said, are either to open a blank new tab (option available either via settings of new right side gear icon) or, the new default, one that displays tiled home page links to your most visited and other ‘suggested’ web sites.
If one of those web site home page tiles is blocked by AVAST then any new tab opened will result in the error messages the OP described.
I really think that is the best explanation for the new tab error message with FF. But it doesn’t explain why in the first place AVAST+ FireFox is blocking the web site mentioned whilst AVAST+Pale Moon isn’t. That is the real problem. If that is resolved then it should also fix the error message/new tab issue too.