If I understand correctly, the "PDF Browser Plugin 2.4.4" plugin is the Schubert|it plugin.

To download, what if you change your PDF preference to "Save File" or "Always Ask"? You can try that here:

Firefox menu > Preferences > Applications

If you prefer to use the plugin to view the file inside a Firefox tab, but Firefox cannot find the plugin, it could be related to change in the folder structure of the Mozilla folder in Firefox 21. Did it work correctly in Firefox 20 and earlier?

Changed PDF preference to save file. Did not down load. I downloaded this plug in because adobe wasn't working either. Worked fine until this update of firefox. Any other ideas, quite frustrating.

I should have asked before. What exactly is happening when you click the link to the PDF: are you getting a blank tab? Are you getting the built-in Firefox PDF Viewer in a tab?

the little wheel spins in the tab, stops and then nothing. Nothing appears. I don't get the built in firefox pdf viewer tab-or I haven't seen it. Where is it and how would I get that to appear? I'm willing to try anything, the pdfs I have to download are on a website that only allows pdfs to be downloaded on firefox not safari. I don't like it, but I didn't write the program, I think it was written by a non mac educated programmer!

To use the built-in PDF viewer, change the drop-down in the Application preferences to "Preview in Firefox". When it works correctly -- it's not compatible with all PDFs yet -- you see a reasonable facsimile of the PDF content and there is a download button to save the file on the viewer toolbar.

I disabled the other reader in plug-ins. Went to applications and selected preview in firefox. Again nothing happened. Should I reinstall firefox and see if that is the issue? I'm on day 2 of trying to figure this out, quite the puzzler.

If the problem only affects the one website, there's something else I suggest trying first. When you have a problem with one particular site, a good "first thing to try" is clearing your Firefox cache and deleting your saved cookies for the site.

(1) Bypass Firefox's Cache

Use Command+Shift+r to reload the page fresh from the server.

Alternately, you also can clear Firefox's cache completely using:

Firefox menu > Preferences > Advanced

On the Network mini-tab > Cached Web Content : "Clear Now"

If you have a large hard drive, this might take a few minutes.

(2) Remove the site's cookies (save any pending work first). While viewing a page on the site:

• Tools menu > Page Info > Security > "View Cookies"
• click globe/lock icon in the address bar > More Information > Security > "View Cookies"

This will open a dialog where you can remove that site's cookies individually.

Then try reloading the page. Does that help?

Did the above. This time the little wheel in the tab button started turning, then turned blue as it was turning (so I thought it was going to work because I had never seen that happen). However once the wheel stopped turning no documents appeared. Still have preview in firefox selected. Do the documents download to a file somewhere? Thanks.

When using a viewer, the file is downloaded to a temporary location, but I'm not sure where (i.e., Temp folder, Firefox cache).

If PDFs used to open in the Adobe plugin in Firefox, then a change in Firefox 21 might be affecting that. A shared folder where some plugins were located before has changed and the files need to be copied over. I don't know the correct folders on Mac, as I've only seen discussions about Flash on Linux and Windows Media Player and AlternaTIFF on Windows. Hopefully someone else can advise on that issue.

One other thing to check would be extensions, either updates or possible conflicts. I noticed you have one named PDF Viewer, which could be conflicting with the built-in viewer. Could you try disabling that one here:

Tools menu > Add-ons > Extensions category

Also, while on that screen, I'd click the "gear" icon and Check for Updates.

Thanks for your patience. Tried that suggestion. Did not work. I've been searching around my hard drive for a folder that the downloads could to. However under down load library it shows no download history. So I'm guessing the pdf is able to be found but not downloaded.

If you have any other thoughts I am happy to try anything.

Thanks so much. Wish this could get resolved.

There are known issues with the Adobe PDF plugin not working properly on Mac and the recommendation is to use the external Adobe Reader application or Preview application instead.

I have tried the external adobe reader and the preview options under preferences, application, portable document format.

These pdf files will not download. Nothing appears.

I assume this site doesn't have the kind of links that let you right-click and Save Link As to get the file? Is it possible to test with another computer to see whether it has the same issue? If so, perhaps you can complain to the site that it is not possible to download in either Safari or Firefox.

If it's a site that doesn't require a login, can you post a URL for testing?

No, the site requires a password. And I no links to right click. I'll try another computer and see if I can access it that way. I'll post and let you know the results.

Tried two other computers. Got it to work on a macbook air. I have no idea why it worked on that computer. The interesting thing was that when I went to preferences, applications and Portable Document format the choices on that computer were preview with firefox, always ask, save file, Use Preview (default), Microsoft word, use other. I don't get all those options on my imac.

Try to delete the mimeTypes.rdf file in the Firefox profile folder to reset all file actions.

• http://kb.mozillazine.org/mimeTypes.rdf
• http://kb.mozillazine.org/File_types_and_download_actions#Resetting_download_actions

Tried that too. I think it may be a pop up problem. Even though I have the site listed as an exception to allow pop ups it doesn't. When I uncheck block pop up windows box in content it still doesn't allow pop ups. I don't even get that box that appears on the top of the screen saying firefox blocked the popups...etc. The computer that finally pulled the downloaded pdfs got that box to show.

Ive uninstalled and reinstalled firefox. Still does not work. I can't use the other computer it worked on because it's not mine.

I am baffled.

cor-el's suggestion would address the choices in the drop-down in your application preferences.

Firefox stores a range of site-specific permissions which could affect particular site functions. Many of these can be edited using one of the following:

• When viewing a page on the site, click the padlock/globe icon in the address bar, then More Information > Permissions tab
• When viewing a page on the site, Tools menu > Page Info > Permissions tab
• In the address bar, type or paste about:permissions and then enter the site in the search box in the left pane

But... it's not always possible to flush everything out. There is a more drastic method called "Forget about this site" which clears every setting, history entry, and bookmark for the site. Hopefully that won't be necessary.

Thanks. Checked permissions, Pop ups are allowed. Reinstalled Firefox and still not working. This is so bizarre. I downloaded opera and I can access files on opera, but not on firefox (or safari for that matter). No idea what to do next.