The Reset Firefox feature can fix many issues by restoring Firefox to its factory default state while saving your essential information. Note: This will cause you to lose any Extensions, Open websites, and some Preferences.

To Reset Firefox do the following:

1. Go to Firefox > Help > Troubleshooting Information.
2. Click the "Reset Firefox" button.
3. Firefox will close and reset. After Firefox is done, it will show a window with the information that is imported. Click Finish.
4. Firefox will open with all factory defaults applied.

Further information can be found in the Refresh Firefox - reset add-ons and settings article.

Did this fix your problems? Please report back to us!

If you used the Firefox Reset you will now have lost your extensions and may now wish to reinstall:

   Easy YouTube Video Downloader 6.7
   eWallet AutoPass 1.0.2.31861
   Exif Viewer 2.00
   Feedback 1.2.2
   TinEye Reverse Image Search 1.1
   Troubleshooter 1.0a

Sorry you are having problems. This is a change that a sizeable minority seem not to like. I suspect the implementation policy for this could have been better.

As I understand it the built-in PDF viewer

• is released but far from feature complete or fully developed.
• does not print, although that is a partially developed feature
• has known issues, that it is anticipated will be fixed in various future releases of Firefox: including problems sometimes saving files
• it does not at the moment deal with interactive editable pdf forms
• some users and web site owners are unhappy with the situation. When compared with Adobe use there are compatibility issues or feature differences.

I have not checked, but presume the integrated PDF viewer is now the default setting, in which case the Firefox Reset feature will no doubt ensure Firefox is set to use it.

I think you will need to read and consider following the advice in

• View PDF files using Firefox’s built-in viewer

I cannot find any FireFox Reset in the program. Where is it?

The problem I am having is that NOTHING will open a PDF now. Not FF, not Acrobat...NOTHING. All FF wants to do is to download the pdf files.

Hello tommc4, DON'T reset firefox, see the link How to disable the built-in PDF viewer and use another viewer in John99's reply.

thank you

That answer did not do anything. I am thinking I had a corrupt FF config file. I have already run the reset, and checked, the internal PDF viewer kicked in. I changed it to Acrobat, closed out of FF, then restarted it, went to a PDF, and it is working properly now.

I really think Mozilla made a big headache by trying to build in a PDF reader. The Acrobat one is free, and it is the best way to go. Why reinvent the wheel. I have wasted a number of hours on this, and I have hated it. I almost dumped FF over this issue. Quit trying to add stuff that is not needed - focus on what IS needed!

Just my 2c worth!

Now, to figure out how to get the tabs BELOW the URL line....

Glad you did sort it out in the end.

As an aside
There were I believe good intentions behind the changes with the PDF viewing. Partly IIRC because of

• taking the long view of Firefox development,
• and the view on security implications of using plugins as opposed to similar features that may now be integrated in the browser.
• the concept that open source methods should be used where available rather than commercial/proprietary software

This is however not really the place for such discussions. We do not cover development issues here, we cover user support and fixes.

Tabs

Now, to figure out how to get the tabs BELOW the URL line.... 

It it is probably best to start a new thread using /questions/new
This a slightly contentious subject. Again I understand decisions were made for good reasons regarding future development. Of course as ever Firefox is highly configurable.