By default, Firefox should allow pop-ups generated by you clicking a message, link or button. Normally, no exception is required.

For your exception, did you set it for google.com (should cover mail.google.com, etc.)?

Is it possible that one of your extensions is adding an extra layer of popup protection on top of the built-in feature? You can review your extensions on the Add-ons page. Either:

• Ctrl+Shift+a
• "3-bar" menu button (or Tools menu) > Add-ons

In the left column, click Extensions. Then peruse the list on the right for anything pop-up or script or security-related. If any has an Options button, you could check that for possible settings.

If there's nothing obvious, could you test in Firefox's Safe Mode? That's a standard diagnostic tool to deactivate extensions and some advanced features of Firefox. More info: Diagnose Firefox issues using Troubleshoot Mode.

If Firefox is not running: Hold down the Shift key when starting Firefox.

If Firefox is running: You can restart Firefox in Safe Mode using either:

• "3-bar" menu button > "?" button > Restart with Add-ons Disabled
• Help menu > Restart with Add-ons Disabled

and OK the restart.

Both scenarios: A small dialog should appear. Click "Start in Safe Mode" (not Refresh).

Any difference?

I have an exception for both google.com and another for mail.google.com

I tried restarting Firefox in Safe Mode, it did not resolve the issue.

Did you try completely turning off the pop-up blocker as a test?

Yes I tried that just now. I turned off the pop-up blocker completely and restarted the browser. It did not work.

I'm posting a screenshot of the error message I always receive.

Oh, that explains it. The redirect block is a completely different setting.

"3-bar" menu button (or Tools menu) > Options > Advanced

On the General mini-tab, in the Accessibility section, uncheck the box for "Warn me when websites try to redirect or reload the page"

Does that fix it?

Thank you!! Yes it did. I thought it was a pop up issue.