I have an Mac and a PC which I just updated to 50.0.2. Now, when I want to close down FireFox on my PC, I get all these web pages, some of which are X-rated. Why is this happening? Also, I get asked to update Flash Player and other things from companies I've never heard of. Where is this coming from? The new update? I ran Windows Defender and it was fine. I am typing this on my Mac because it's easier for me so, none of the info below applies. Help!