I'm using Firefox for Android on a Kindle fire tablet. Just to be very clear: I am not trying to block a website. I'm trying prevent a site from opening other sites in other tabs. I cannot find anything about pop-ups in the settings, and I don't even know if it's technically a “pop-up” if it is opened in a new tab Every potential answer I've been able to find on the web to this question begins with "enter '''about:config''' in the address bar." But when I to try enter this and then press the enter button, nothing happens. Just a blank screen. Am I doing something wrong? Is there another way to go about this? I thank you in advance. I'm very frustrated. It seems like it should be such a simple thing to do in a security-minded browser like Firefox