Please provide more details of the problem. All websites, many, some? Any error messages?

I have tried every solution that I can find online. I cannot get rid of the popup blocker. I have unchecked the box in preferences many times. Since "resetting" firefox junk pages pop up and under, but it blocks pages that I want to go to from gmail. No error messages

What pop-up blocker? Is it an add-on?

Start Firefox in Safe Mode {web Link} by holding down the <Shift>
(Mac=Options) key, and then starting Firefox. A small dialog should appear. Click Start In Safe Mode (not Refresh).

Is the problem still there?

Started in safe mode. It still blocks when I click on my emails. garbage still pops up.

Turned off accelerator. Still blocking what I want to go to but lets junk in.

FredMcD said

What pop-up blocker? Is it an add-on?

Just In Case;

Mac Malware Scanners https://discussions.apple.com/message/29938930#29938930

You can also try https://www.malwarebytes.org/antimalware/mac/index.html

I think it is the pop-up blocker that comes with firefox. Trashed Java and non apple cleaning apps. Downloaded Malwarebytes and ran it. still have the same problem.

See if this helps;

Adblock Plus {web link} Blocks annoying video ads on YouTube, Facebook ads, banners and much more. Adblock Plus blocks all annoying ads, and supports websites by not blocking unobtrusive ads by default (configurable).

Adblock Plus Pop-up Addon {web link} Adblock Plus Pop-up Addon extends the blocking functionality of Adblock Plus to those annoying pop-up windows that open on mouse clicks and other user actions.

Forum; Adblock Plus Homepage {web link}

I'm trying to get rid of the popup blocker.

I found a solution, I'm getting rid of Firefox.