Type about:preferences#content<enter> in the address bar Under Content turn on Block pop-up windows. To its right, press Exceptions. List any sites that you do not want pop-ups to be blocked.

Separate Issue; Your System Details shows;

Installed Plug-ins

Adobe PDF Plug-In For Firefox and Netscape 11.0.07 Adobe PDF Plug-In For Firefox and Netscape 15.10.20056
Having more than one version of a program may cause issues. You must remove the older programs. Then get the current full installer.

Adobe PDF Plug-In For Firefox and Netscape: Adobe Reader Version 2015.009.20069 Note: McAfee Security is offered in the download.

This is not the answer. I can't list all exceptions--indeed, I do NOT WANT ANY pop-ups blocked. That's what I UNCHECKED the "Block pop-up windows" box. Does this not do what it says it does?

As for the plug-ins for Netscape--I have not used Netscape for over a decade! And I have a NEW installation of Windows 10, not an upgrade. Where would such plug-ins come from? I have disabled them, but don't see any way to remove them.

Thanks for pointing that out.

What pref on about:config are you talking about?

You can check for problems with preferences and delete possible user.js and numbered prefs-##.js files and rename (or delete) the prefs.js file to reset all prefs to the default value including prefs set via user.js and prefs that are no longer supported in current Firefox releases.

• http://kb.mozillazine.org/Preferences_not_saved
• http://kb.mozillazine.org/Resetting_preferences

Start Firefox in Safe Mode to check if one of the extensions (3-bar Menu button/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem.

• Switch to the DEFAULT theme: 3-bar Menu button/Tools > Add-ons > Appearance
• Do NOT click the Reset button on the Safe Mode start window

• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

Okay, I reset my prefs and when I reviewed options again, the block pop-ups box was checked again! So I unchecked the box, but every #@$%^&*( time I click on a URL, including the ones in this message, I have to click on accept for the pop-up.

BTW, the plug-in you mentioned as being for Netscape in reality is for Netscape AND Firefox, so no need to disable that, I think....

Perhaps we are talking about the wrong thing here--maybe my terminology of "pop-ups" is wrong.

What I'm talking about is what happens when I click on a URL, and a new tab opens with the message "Firefox prevented this page from automatically redirecting to another page." with a box to the right that says "Allow."

I have also selected the option to "Open new windows in a new tab instead." Is this what is causing the problem. Please help me understand this!

See:

• Firefox > Options/Preferences > Advanced > General : Accessibility : [ ] "Warn me when web sites try to redirect or reload the page"

The setting in "Options > Advanced > General" is meant as an accessibility feature, as you can see by the label of that section, so that people with disabilities or people who use screen readers do not get confused and is not meant as a safety protection to stop redirecting.

See also:

• https://support.mozilla.org/kb/settings-network-updates-and-encryption#w_general-tab

• http://kb.mozillazine.org/accessibility.blockautorefresh
• http://kb.mozillazine.org/Accessibility_features_of_Firefox

This is also happening to me. I use a software program that you access through your web browser, and it needs to allow pop ups to function, and EVERY single time it says: "Firefox has prevented this site from opening a pop up window", and I am asked to allow this pop up. It is incredibly frustrating as I need to hit 'allow' 100 times a day. I have also unchecked "don't allow pop ups" within Firefox, and I have also added the url as a 'safe' url, and it still asks me. It seems to be a total malfunction within Firefox. Can anyone help with this??