This might be of help towards your issue. Seeing as the file opens up as normal, and then as well opens up a blank tab. https://support.mozilla.org/en-US/kb/firefox-repeatedly-opens-empty-tabs-or-windows

None of this was helpful. Still opens a blank page unless I click to save rather than open. shouldn't do this.

Try getting rid of this extension and see if that extra tab stops appearing:

PDF Download 3.0.0.2.1-signed.1-signed ({37E4D8EA-8BDA-4831-8EA1-89053939A250}) (Inactive)

You might want to consider creating a new Profile and installing only the extensions that you currently use. That's a "lot of baggage to be carrying around" - Profiles don't last forever and can really slow Firefox down with a load of inactive / out-of-date extensions "hanging around".

I don't see that extension anywhere to get rid of it. I will see if creating a new profile works. But, I only see my current extensions. In my profile, I opened extensions and still could not find it. Is it tobe found somewhere else?

Extensions that do not have a "Remove" button are installed globally by other software and are not under control of the Firefox extension manager. Globally installed extensions are usually found via a registry scan or are installed in a location that Firefox scans for installed extensions.

• https://developer.mozilla.org/Installing_extensions
• https://developer.mozilla.org/Adding_Extensions_using_the_Windows_Registry

Extensions installed globally need to be removed via the settings (Options/Preferences) of the program that has added this extension or this program has to be uninstalled via "Control Panel -> Programs". In Firefox you can only disable such an extension.

You can find the install location of a specific extension in the extensions.json file in the profile folder. You can open the extensions.json file in the Scratchpad and search for this extension. The descriptor field should list its install location.

The following has been true for a long time. Is there something new?

When a website has coded the PDF link to open in a new window or tab, and Firefox determines that it really should be downloaded, then Firefox will close the new window or tab automatically.

However, if you divert the link to a new window or tab (e.g., by Ctrl+clicking, Shift+clicking, using right-click > Open Link in New Tab) then Firefox may leave the tab/window open.

Is it possible that Tab Mix Plus is emulating you opening a link in a new window or tab for the problem PDFs?

Well, no. I've had Tab Mix Plus for a long time and made no changes. It is set to open LINKS in a new tab, NOT PDFs and it has only started doing this for a few weeks.

kaylaartist said

Well, no. I've had Tab Mix Plus for a long time and made no changes. It is set to open LINKS in a new tab, NOT PDFs and it has only started doing this for a few weeks.

Hmm, if you don't click a link to open the PDF, how does it work, do you click a button?

Firefox had a change at the end of June related to new tabs for downloads, to fix a problem where the wrong tab was being closed. Example of that problem: opening a PDF document closes underyling window

This might have caused an incompatibility with Tab Mix Plus or another extension. ??

To rule out extensions as a factor, do you want to test in Firefox's Safe Mode? In Safe Mode, Firefox temporarily deactivates extensions, hardware acceleration, and some other advanced features to help you assess whether these are causing the problem.

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 improvement? (More info: Diagnose Firefox issues using Troubleshoot Mode)

Here's what I did. Different than your suggestion, tho. Went to Tab mix plus and added pdf files extension as an exception to 'prevent blank tab when downloading files" and that seems to work

kaylaartist said

Here's what I did. Different than your suggestion, tho. Went to Tab mix plus and added pdf files extension as an exception to 'prevent blank tab when downloading files" and that seems to work

Gee, that should be the default setting! Thanks for reporting back on that.

Ok, that was fine. However, new Firefox update does not have TAb mix plus. Started opening blank tabs again. Now what?