Safari problem on El Capitan
A friend is running an iMac mid 2007. The last effective OS was El Capitain for that model of iMac. She's been getting this pop-up for months now, and can't figure out what is causing it or what to do. See attached 'pop-up'.
I'm trying to help her solve this. It's keeping her from Browsing the web. The available Firefox won't run on this older OS. and I can't just re-install her Safari. I'd need to re-install El Capitain, which I'm not sure is possible.
Any suggestions would be most appreciated ...
Ben
[Re-Titled by Moderator]