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Can't open, download or view PDFs - Tried all fixes recommended on this site!


I updated Firefox yesterday and now I am suddenly unable to open, download or view PDF documents on my mac. I just get a blank page in Firefox when I click on a PDF link.
I tried every fix I could find on this forum and others:
Disabling both the Acrobat NPAPI Plugin and the Acrobat Reader Plugin
delete the mimeTypes.rdf file in the Firefox Profile Folder to reset all file actions.
installing another PDF reader plug-in
Cleared download history
Reset Firefox
Checked status of Download Folder - no 'user set' values
Reinstalled Firefox
Fixed all Mac Permissions
Still same thing PDF tries to open in a new tab - I just get a blank window… even when my PDF Preferences are set for the pop-up dialogue to show so I can choose whether to save, open or view.
AND my Firefox preferences are set for viewing in Acrobat Pro X (this was how I had it set up before the update and had no problems - all PDFs opened in this application. (my preferred)

I am stumped. Anyone have any fresh ideas? HELP!! :) Thank you

Modified by cor-el

Additional System Details

Installed Plug-ins

  • Displays Java applet content, or a placeholder if Java is not installed.
  • Shockwave Flash 11.4 r402
  • The QuickTime Plugin allows you to view a wide variety of multimedia content in web pages. For more information, visit the QuickTime Web site.
  • Microsoft Office for Mac SharePoint Browser Plug-in
  • iPhoto6
  • npmnqmp 071505000006


  • User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:18.0) Gecko/20100101 Firefox/18.0

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10783 solutions 97065 answers

The Adobe Reader plugin may not be working properly on Mac.

Disable the Adobe Reader plugin in Firefox (Tools > Add-ons > Plugins) and use the external Adobe Reader application or Preview application instead.

PDF files may be found under entries like Portable document or Adobe PDF document.

  • Firefox > Preferences > Applications > Adobe PDF document : Use Adobe Reader

Question owner

Sorry for the giant paragraph - there were actually paragraph returns when I typed my question. At any rate, had already tried that, with no success.

HOWEVER I did eventually solve the problem by REMOVING NITRO PDF READER (which had been functioning fine prior to Firefox update) extension. Instant fix.

Hope this helps someone else. That was a lot of time and energy to figure out the culprit.