Here is a screen shot of the dialog box that opens after clicking a .pdf file URL on website "X" (This happens anytime I try to open a link that is a .pdf file). If I use Internet explorer I am able to open the .pdf file with no problem in either a new INTERNET EXPLORER TAB or sometimes they open up with the full ADOBE viewer. I therefor surmise that it is something with FIREFOX that prevent me from viewing a .pdf file.

If I save the file to my harddrive, I am able to open the .pdf file with no problem using ADOBE.

You can change the action for Portable Document Format (PDF) from Preview in Firefox to use the Adobe Reader or set to Always Ask in "Firefox > Options/Preferences > Applications".

You can set the pdfjs.disabled pref to true on the about:config page to disable the build-in PDF viewer.

You can check the value of the plugin.disable_full_page_plugin_for_types pref on the about:config page and remove the application/pdf part if present or reset the pref to the default via the right-click context menu.

• http://kb.mozillazine.org/about:config

See also:

• https://support.mozilla.org/kb/view-pdf-files-firefox-without-downloading-them

Cor-el,

  Your link to the https://support.mozilla.org/kb/view-pdf-files-firefox-without-downloading-them did the trick.  I had to scroll down about half way down to find the "Portable Document Format (pdf)" entry.  How mine got changed I don't know because I surely didn't do it.  I am not sure if this was set with the newest update to either version 21.0 or the earlier version of FIREFOX update?

I did not change anything in my ABOUT:CONFIG file. This is what I currently have and have left it like this;

plugin.disable_full_page_plugin_for_types;application/pdf,application/vnd.adobe.xfdf,application/vnd.fdf,application/vnd.adobe.xdp+xml

Thank you very much!!

I had the same problem, but I got it right by the following methods:

Go to Firefox > Options > Applications > Portable Document Format (PDF)

And for Portable Document Format (PDF) set the status as "Use Adobe Acrobat (in Firefox)"

Done

Now the PDF file opens within the Firefox browser without any need to download the file to open.