In Firefox 56, that option was removed from the settings page. However, you can still set that option using a different method:

1. Type about:config in your Firefox address bar.
2. Bypass the security warning (don't worry, we'll be careful).
3. Find accessibility.blockautorefresh
4. Double click it to change the value to true.
5. Restart Firefox.

This should enable that feature for you.

However, it sounds more like the issue you are having has something to do with the built-in popup blocker in Firefox. Nevertheless, try enabling the redirection feature and see if that makes an improvement.

Hope this helps.

Thanks. The exact problem is when going into a website something altogether nasty came up, this happened twice. It appears I'm going into a website that is perfectly in line with what I searched for and I get a full screen page of something completely different and ugly, its not just a small pop up.

I scanned for malware and nothing came up.

There are certain websites that will do this (typically less trustworthy websites) and there are certain ways that websites can bypass the popup blocker by tricking Firefox into thinking you are trying to open the page legitimately.

If this issue is exclusive to a website or just a few websites, my guess is that it's probably caused by an illegitimate website. In that case, there's usually not a whole lot you can do other than avoiding the website.

If you have the issue on many of the websites you visit and your malware scanner doesn't detect anything, it could be an issue caused by an extension installed on Firefox. You can try running in Firefox Safe Mode to see if the problem goes away in there. If it does, it's likely an extension.

Hope this helps.