OK Thank you. I will wait & watch. I appreciate your assistance.

OK, Thank you. It is now clean. I presume that means the problem has probably been removed.

Sorry, I do not understand "clean profile"

Yes. The only thing open on Opera is Bookmarks.

The only extension I have on Opera is Roboform, and it is clean.

1. I have adware scanner in place & running.
2. This only happens when I have Opera running in the background, it is not my default browser & I mostly have not started it - I only start it when I expect to use it, afterwards I sometimes leave it running in the background and that is when this happens.
   After the popup appears as soon as I remove it, Opera opens up & a new tab opens with the porn site.
   Clearly, if it is not related to Opera, it would open in the default browser, Firefox.

My system is scanned constantly by two different programs, Norton Security and Advanced System Care Ultimate.

I cleared the page before it fully opened. As a result, it does not appear in History.
It appears first as a pop-up, and then Opera starts to open a webpage.
I had a few a couple of days ago, and three times this afternoon. None since.
If it happens again, I will get the URL and a screen shot. It has always been the same one rather than different ones.

I keep getting porn ads even though I have ad blocking in place. How do I stop them?