Do you use a Facebook share add-on?

No, and I never have. I just utilize the share buttons that are on sites , as is the rule nowadays. Like I said, many times it works just fine and then at other times, it does this phantom business where I can't get to it, even though with the mouse over the FF icon, I can see the pop up box there.

Have you tried refreshing your Firefox?

Yes ... and I've cleared cache and restarted. Doesn't help.

Does it work on other computers? Or is it only on your computer that doesn't work?

I only use the one computer.

Does the problem occur on all sites, or is it some specific sites there are problems?

If only some of the sites have problems, it can be because the sites are not made to Firefox and therefore does not work quite optimal.

I never know what sites it will happen on and sometimes it will work on a site and the next time it won't. Today, for example, I was on a site where I've done it before without issue, but today it created the phantoms that I can't access. It's not consistent at all.

Can you post the websites you share from?

So I can check how it works in my Firefox.

When you look at the thumbnail windows or window list on the Taskbar, are any of those windows actually accessible? In other words, if you select one, can you get the window with the actual content, or do you get a blank window, or does it seem the window is completely missing from the screen?

If you are able to activate the window, it is annoying that the pop-up doesn't actually stay in front of the page that launched it, which is what you would expect. Do you have any add-ons, such as security toolbars, that might try to block pop-up windows? You can check 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 cast a critical eye over the list on the right side.

If you can't find the window, sometimes Firefox may open a resizable window off the screen. I'm not sure why that happens; it does seem to happen more to users who sometimes use multiple monitors.

This post has tips on the offscreen issue: https://support.mozilla.org/questions/1069873#answer-748241

When I see the thumbnails, they are images just like I would see different windows of FF open, but when I try to click on them to go to the popups, I can't. Nothing happens. I can even minimize every open window and program and these phantoms are still not visible. The only way I know they are there is by seeing them when I put my mouse over the FF icon on the taskbar.

I don't have any add-ons that deal with this. I've changed nothing and as I've said, it's inconsistent. One time it works on a site and the next time it doesn't. It happens on a variety of sites. I'll click on the share and nothing will happen; I'll think it just didn't take and hit again. Then I go and look at the taskbar and I'll see 2, 3, or more of these pop up phantoms, based on many times I clicked on the share button for Facebook.

I need to update the steps to investigate off screen issues due to a change in Firefox since that older post:

Here are three different approaches. One of them should work!

Firefox Window "off screen" — Arrow Key Method

If you know that Firefox is off to a particular side, you can use the arrow keys to move it back on screen. You only need to move it far enough to be able to click the title bar and then you can drag it the rest of the way.

Make the Firefox tile active on the task bar and press this key combination to start moving the window:

Alt+Spacebar > m

(To clarify, that's Alt+Spacebar to open the window control menu, then the letter m to start moving the window.)

Press the arrow key for the direction you want to move the window, e.g., press the left arrow key to move the window left. Press the Enter key to complete the move.

Firefox Window "off screen" — Maximize + New Window Script Method

If Firefox is nowhere to be found but you know it's out there, try this method.

Make the Firefox tile active on the task bar and press this key combination to maximize the window:

Alt+Spacebar > x

(To clarify, that's Alt+Spacebar to open the window control menu, then the letter x to maximize the window.)

If that works, try this:

(1) Copy the following line of code to the clipboard (it's all one line...):

newwin=window.open(window.location.href, "_blank", "width=640,height=480,menubar,toolbar,personalbar");newwin.moveTo(0,0);

(2) In the maximized window, press Ctrl+Shift+k to open the web console.

(3) Press Ctrl+v to paste the line of code next to the caret (») then press Enter to run it. A new copy of that page should open in a window positioned at the top left of the screen.

(4) Switch back to the maximized window and close it first, before doing anything in the new window.

Firefox Window "off screen" — Remove Settings File

If you can't move or maximize Firefox, you can rename or delete the settings file that stores the last window position.

(1) Open your currently active Firefox settings folder (AKA Firefox profile folder).

From the Start menu (Run box or search box), paste this into the search box and press Enter:

%APPDATA%\Mozilla\Firefox\Profiles

This should open a window showing one or more Firefox profile folders. If you have multiple folders, look for the most recent. Click into your profile folder.

(2) Switch back to Firefox and Exit completely. In some cases, you might need to right-click the Taskbar icon and Close All Windows.

(3) Wait a few moments for Firefox to finish updating files in your profile folder, then rename xulstore.json to something like xulstore.bad. If you see a file named localstore.rdf, rename that one to localstore.bad.

(4) You're done with your profile folder and you can restart Firefox now.

Any luck?

Orrymain said

This just happened to me again and I have no idea why. I'll be on a website, maybe a news site, a store site, or wherever, in my browser -- Firefox (version is irrelevant because this has happened for a long time with lots of different versions) -- and I'll click on the share button so I can share something on Facebook. The pop up will not appear, but if I put my mouse over the taskbar icon for Firefox, the pop up shows up. In fact, there could be multiples, depending on how many times I've clicked the share button. Many other times, it works just fine, but on these occasions, they are like phantom pop ups. I can't get to them to share what I want. Anyone know why?

Y'know, I have used that arrow key to move thing before when the main browser screen was open, but never on a pop up. Wish I'd thought to try it. Thanks so much for the push to check that out 'cause it worked!!  :}