• Posted Nov. 22, 2012, 12:19 p.m. - 10 years, 4 months ago

Helpful Fixes for Firefox Not Opening PDF Files on a Mac

Some people have had problems opening PDF files when using Firefox on a Mac running OS 10 (Mountain Lion).  This happened after an Adobe Reader update.  The symptom is a blank PDF view.


The source of the problem appears to be an incompatibility between Adobe’s NPAPI reader plugin and either the 64-bit Mountain Lion or Firefox browser.

There have been several fixes that various people have found and we have found them.  Here are some of the fixes.

Throwawayacct1 says:

I’ve found another workaround to this problem. If you open Firefox 11 in 32-bit mode, it will be able to display PDF files.

To open Firefox in 32-bit mode, quit Firefox, go to the Applications folder, right-click on Firefox and click on “Get Info”.

Then, under General, you should see a checkbox where you can have Firefox open in 32-bit. Close this window and restart Firefox and you should be good to go.

D0ckw0rka tells us:

As workarround you could do a “rightklick” and “save” as the pdf will work with the Acrobat viewer itself

Underwater has another solution:

Go to [Menu] Tools/Add-Ons/Plugins and disable the Adobe Acrobat NPAPI 10.1.3 reader plugin. It seems to be a common problem, and Adobe will fix it. But for now, this may work.

With this plugin disabled you’ll see your download dialog box again.

If you have this problem, which of these solutions works for you?  Have you discovered any other solutions?

We found these solutions in the Mozilla Support Group.