see

• PDF files are blank or cause an error message on Mac

I disabled the Adobe plugin years ago. In any case, my problem isn't that PDFs are blank or can't download. It's that the built-in Firefox viewer isn't working.

Thanks, though.

Are you getting a error message, you may have to reset firefox.

• Refresh Firefox - reset add-ons and settings

No. No error messages. Firefox will simply download the PDF file whenever I click on a link, or when I right-click on a link and select "Open in new tab". It's like Firefox doesn't know it's supposed to be able to read PDFs.

In order to be able to find the correct solution to your problem, we require some more non-personal information from you. Please do the following:

• Click the Firefox button at the top left, then click the Help menu and select Troubleshooting Information from the submenu. If you don't have a Firefox button, click the Help menu at the top and select Troubleshooting Information from the menu.

Now, a new tab containing your troubleshooting information should open.

• At the top of the page, you should see a button that says "Copy text to clipboard". Click it.
• Now, go back to your forum post and click inside the reply box. Press Ctrl+V to paste all the information you copied into the forum post.

If you need further information about the Troubleshooting information page, please read the article Use the Troubleshooting Information page to help fix Firefox issues.

Thanks in advance for your help!

As requested:

 Application Basics

       Name
       Firefox

       Version
       22.0

       User Agent
       Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:22.0) Gecko/20100101 Firefox/22.0

       Build Configuration

         about:buildconfig

 Extensions

       Name

       Version

       Enabled

       ID

       Adblock Plus
       2.2.1
       true
       {d10d0bf8-f5b5-c8b4-a8b2-2b9879e08c5d}

       Adblock Plus Pop-up Addon
       0.5
       true
       adblockpopups@jessehakanen.net

       Google Analytics Opt-out Browser Add-on
       0.9.6
       true
       {6d96bb5e-1175-4ebf-8ab5-5f56f1c79f65}

       Old Default Image Style
       2.2
       true
       olddefaultimagestyle@dagger2-addons.mozilla.org

       Status-4-Evar
       2012.07.08.17
       true
       status4evar@caligonstudios.com

       Stylish
       1.3.1
       true
       {46551EC9-40F0-4e47-8E18-8E5CF550CFB8}

       Adobe Acrobat - Create PDF
       1.1
       false
       web2pdfextension@web2pdf.adobedotcom

       Greasemonkey
       1.5
       false
       {e4a8a97b-f2ed-450b-b12d-ee082ba24781}

       NoScript
       2.6.4.2
       false
       {73a6fe31-595d-460b-a920-fcc0f8843232}

       PDF Viewer
       0.7.1
       false
       uriloader@pdf.js

       PrivacyChoice TrackerBlock
       2.2
       false
       trackerblock@privacychoice.org

       TACO with Abine
       4.50
       false
       optout@dubfire.net

 Important Modified Preferences

     Name

     Value

       accessibility.typeaheadfind.flashBar
       0

       browser.cache.disk.capacity
       25600

       browser.cache.disk.smart_size.first_run
       false

       browser.history_expire_days.mirror
       180

       browser.places.smartBookmarksVersion
       4

       browser.search.update
       false

       browser.search.useDBForOrder
       true

       browser.startup.homepage
       http://www.metafilter.com/

       browser.startup.homepage_override.buildID
       20130618035212

       browser.startup.homepage_override.mstone
       22.0

       browser.tabs.loadInBackground
       false

       browser.tabs.onTop
       false

       browser.tabs.warnOnClose
       false

       browser.tabs.warnOnOpen
       false

       browser.urlbar.autocomplete.enabled
       false

       browser.zoom.full
       false

       dom.disable_window_move_resize
       true

       dom.event.contextmenu.enabled
       false

       dom.mozApps.used
       true

       dom.w3c_touch_events.expose
       false

       extensions.lastAppVersion
       22.0

       font.default.x-western
       sans-serif

       font.internaluseonly.changed
       false

       font.name.monospace.x-western
       Arial Unicode MS

       font.name.sans-serif.x-western
       Arial Unicode MS

       font.name.serif.x-western
       Adobe Caslon Pro

       font.size.variable.x-western
       13

       gfx.blacklist.webgl.msaa
       4

       gfx.color_management.enablev4
       true

       image.mem.decodeondraw
       false

       network.cookie.cookieBehavior
       1

       network.cookie.prefsMigrated
       true

       network.dns.disableIPv6
       true

       places.database.lastMaintenance
       1375198743

       places.history.enabled
       false

       places.history.expiration.transient_current_max_pages
       104858

       places.history.expiration.transient_optimal_database_size
       161061272

       places.last_vacuum
       1296483807

       plugin.disable_full_page_plugin_for_types

       plugin.importedState
       true

       plugin.state.adobeexmandetect
       0

       plugin.state.adobepdfviewernpapi
       0

       plugin.state.amazonmp3downloaderplugin
       0

       plugin.state.iphotophotocast
       0

       plugin.state.java
       0

       plugin.state.officelivebrowserplugin
       0

       plugin.state.pdf browser plugin
       2

       plugin.state.wacomnetscape
       0

       plugin.state.wacomtabletplugin
       0

       print.macosx.pagesetup-2
       PD94bWwgdmVyc2lvbj0iMS4wIiBlbmNvZGluZz0iVVRGLTgiPz4KPCFET0NUWVBFIHBsaXN0IFBVQkxJQyAiLS8vQXBwbGUvL0RURCBQTElTVCAxLjAvL0VO

       print.print_bgcolor
       true

       print.print_bgimages
       true

       print.print_command

       print.print_downloadfonts
       false

       print.print_evenpages
       true

       print.print_footerleft

       print.print_footerright

       print.print_headerleft

       print.print_headerright

       print.print_in_color
       true

       print.print_margin_bottom
       0.5

       print.print_margin_left
       0.5

       print.print_margin_right
       0.5

       print.print_margin_top
       0.5

       print.print_oddpages
       true

       print.print_orientation
       0

       print.print_page_delay
       50

       print.print_pagedelay
       500

       print.print_paper_data
       0

       print.print_paper_height
       11.00

       print.print_paper_size_type
       1

       print.print_paper_size_unit
       0

       print.print_paper_width
       8.50

       print.print_printer

       print.print_reversed
       false

       print.print_scaling
       1.00

       print.print_shrink_to_fit
       true

       print.print_to_file
       false

       print.print_unwriteable_margin_bottom
       56

       print.print_unwriteable_margin_left
       25

       print.print_unwriteable_margin_right
       25

       print.print_unwriteable_margin_top
       25

       privacy.clearOnShutdown.cookies
       false

       privacy.clearOnShutdown.sessions
       false

       privacy.cpd.offlineApps
       true

       privacy.cpd.sessions
       false

       privacy.donottrackheader.enabled
       true

       privacy.popups.showBrowserMessage
       false

       privacy.sanitize.migrateFx3Prefs
       true

       privacy.sanitize.sanitizeOnShutdown
       true

       privacy.sanitize.timeSpan
       4

       security.disable_button.openCertManager
       false

       security.warn_viewing_mixed
       false

       storage.vacuum.last.index
       1

       storage.vacuum.last.places.sqlite
       1373201529

 Graphics

       Device ID
       0x 869

       GPU Accelerated Windows
       1/1 OpenGL

       Vendor ID
       0x10de

       WebGL Renderer
       NVIDIA Corporation -- NVIDIA GeForce 9400 OpenGL Engine

       AzureCanvasBackend
       quartz

       AzureContentBackend
       none

       AzureFallbackCanvasBackend
       none

 JavaScript

       Incremental GC
       true

 Accessibility

       Activated
       false

       Prevent Accessibility
       0

 Library Versions

       Expected minimum version

       Version in use

       NSPR
       4.9.6
       4.9.6

       NSS
       3.14.3.0 Basic ECC
       3.14.3.0 Basic ECC

       NSSSMIME
       3.14.3.0 Basic ECC
       3.14.3.0 Basic ECC

       NSSSSL
       3.14.3.0 Basic ECC
       3.14.3.0 Basic ECC

       NSSUTIL
       3.14.3.0
       3.14.3.0

have you tried safe mode?

• Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems

Occasionally the file that stores your download preferences becomes corrupted. Although in theory it's an editable file, it typically is easier to rename the file and have Firefox regenerate it from scratch. Since Preview in Firefox is the default, hopefully that will restore normal functioning. If it creates new issues, you can reverse the operation (delete the newly generated file and rename the old one back).

Open your current Firefox settings (AKA Firefox profile) folder using

Help > Troubleshooting Information > "Show in Finder" button

Switch back to Firefox and Exit/Quit

Pause while Firefox finishes its cleanup, then rename mimeTypes.rdf to something like mimeTypes.old

Restart Firefox. Any improvement?

jscher2000...If you read my original post, you'll see that I already did that. It didn't change anything.

Hi Thorzdad, sorry, the rest of the thread apparently overflowed my buffer.

If you open that file in a text editor and search for PDF, do you have this?

<RDF:Description RDF:about="urn:mimetype:handler:application/pdf"
 NC:handleInternal="true"
 NC:alwaysAsk="false" />

Do you see any other entries that have both "handler" and "pdf" that might have contrary directions?

There is a preference in Firefox that can disable the built-in viewer independently from your download preferences. You can check it here:

(1) In a new tab, type or paste about:config in the address bar and press Enter. Click the button promising to be careful.

(2) In the filter box, type or paste pdfjs and pause while the list is filtered

(3) Make sure pdfjs.disabled is set to false. (Double-clicking toggles the value.)

_{I didn't notice the reply by jscher2000 so try that first! If that didn't help then try my suggestion:}

You have two pdf plugins showing in your Important Modified Preferences list:

The disabled Adobe PDF Viewer plugin,

plugin.state.adobepdfviewernpapi
      0

...and a PDF Browser Plugin, which is enabled:

plugin.state.pdf browser plugin
      2

Go to the Firefox Tools menu, then click on Add-ons. In the Addons Manager, go to the Plugins panel, find the PDF Browser Plugin and disable it. See if that helps. If not, go to your Firefox Preferences, Applications panel and make sure you have Portable Document Format (PDF) set to "Preview in Firefox".

pdfjs.disabled is set to False.

In the mimeTypes.rdf file, the "handleInternal" flag is true, and the "alwaysAsk" flag is false.

There are a couple of other pdf entries...

<RDF:Seq RDF:about="urn:mimetypes:root">
   <RDF:li RDF:resource="urn:mimetype:application/pdf"/>

</RDF:Seq>

<RDF:Description RDF:about="urn:mimetype:application/pdf"

                  NC:value="application/pdf">
   <NC:handlerProp RDF:resource="urn:mimetype:handler:application/pdf"/>
</RDF:Description>

Are those two possible problems?

AliceWyman...The enabled PDF plugin is the new Shubert plugin I installed just today. Firefox was having this problem long before I installed the new plugin.

Try downloading the Adobe Reader plugin.

Hi Thorzdad, those other two entries are okay. So that definitely leaves the problem unsolved.

If the file downloads without giving you the option to open it:

Could it be related to some kind of downloader add-on? If you already tried Firefox Safe Mode or Firefox Reset, then an add-on issue is unlikely, but if you didn't try either of those, please check your extensions in case one of them is overriding the default handling.

Tools menu > Add-ons > Extensions category

If Firefox displays the Open/Save/Cancel dialog:

Does it show the content type application/pdf matching up with the mimeTypes.rdf entry?

If Portable Document Format (PDF) is set to "Preview in Firefox" in the Applications panel, as shown in this KB article for Windows (Mac OS will be similar except for your default PDF viewer application ...Preview?... and available PDF Browser plugin, Shubert's)

And, if the issue isn't

• a downloader add-on
• another installed add-on (I see you have the Adobe Acrobat - Create PDF extension disabled; you also have PDF Viewer extension v 0.7.1 installed and disabled. I would uninstall PDF Viewer since it's now built-in to Firefox, since Firefox 19) or
• other profile issue (you could also try creating a new Firefox profile for testing)

Then:

Another possible route you could take would be to file a bug report at bugzilla.mozilla.org since your issue may be related to a change made in Firefox 22. For example, see these possibly related bugs (fixed in Firefox 22):

• Bug 738967 - pdf.js doesn't work for embedded PDFs
• Bug 855666 - Firefox Nighty 22.0a1 opens blank page instead of calling the third-party PDF reader plugin

go here! >>> https://support.mozilla.org/en-US/kb/cant-download-or-save-files#w_disable-virus-scanning-in-firefox-preferences

the firefox automatic virus scanner may be preventing your files from opening or working. this will tell you how to turn it off in "about:config". I did it and FINALLY my downloads work!