I don't recommend selecting Firefox as the application to open PDFs. That could lead to an infinite loop.

As shown in the attached screen shot of the Application Options, you usually will have two entries for Adobe, one for the external application, and one for the plugin. Do you have both of those on your list and is the plugin selected? (Note: I'm still using version 11 and not the new DC version, so the icon might be different now.)

Sometimes the file that stores the application handling preferences becomes corrupted. Since the file is difficult to edit, we generally suggest renaming it and letting Firefox start a new one. Here's how:

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

• "3-bar" menu button > "?" button > Troubleshooting Information
• (menu bar) Help > Troubleshooting Information
• type or paste about:support in the address bar and press Enter

In the first table on the page, click the "Show Folder" button. This should launch a new window listing various files and folders in Windows Explorer.

Leaving that window open, switch back to Firefox and Exit, either:

• "3-bar" menu button > "power" button
• (menu bar) File > Exit

Pause while Firefox finishes its cleanup, then rename mimeTypes.rdf to something like mimeTypes.old (in case you need to recover it later).

Start Firefox back up again, and return to the Application options to select your preferred viewer.

Any improvement?

There are some sites that push PDFs as downloads. This is done by setting their content-disposition to "attachment" instead of "inline". In that case, I believe Firefox will not display the PDF in a tab regardless of your application option setting. There is an extension that may allow you to override that behavior: https://addons.mozilla.org/firefox/addon/inlinedisposition/

Still not working. DL the inline add on and renamed the profile folder file to mimeTypes.old. Still shows the downloading arrow and graph of how much has been dl when just trying to view a PDF. I did just notice it's not saving the dl to my computer except in the temp files. Ridiculous thought to show 'dl' when just trying to open, esp a large, document. Thank you so much anyway.

Normally when you view PDF in a tab, it isn't listed on the Downloads panel. Of course, every bit of the file still needs to be downloaded for viewing, but it normally goes into the browser cache instead of the TEMP folder.

I noticed you have a Foxit plugin. Does that work any better than the Adobe plugin?

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 if you want to display PDF documents in Firefox with another application (i.e. not the built-in PDF Viewer).

You can open the about:config page via the location/address bar. You can accept the warning and click "I'll be careful" to continue.

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

Thank you!! Setting plugin.disable_full_page_plugin_for_types pref to default, refreshing the page and opening a PDF actually made it just open for view, lol! Thank you Cor-el.

Jscher, I believe FF came with the Foxit plugin. I don't like it as well because it was cumbersome to save a PDF if memory serves me. Have to go back and check the Foxit features, but after a few uses, I switched back to Adobe. Thank you again. You guys were great.