Hi ed0505, what happens when you access a PDF? For example, do you get a blank tab, a download dialog, nothing happens at all, et cetera.

What do you have set as your handler for "Portable Document Format (PDF)" on the Options page? (Please ignore any other Adobe formats such as fdf.) These articles show the way to view/modify that setting:

• View PDF files using Firefox’s built-in viewer
• Use Adobe Reader to view PDF files in Firefox

Occasionally, users who prefer a plugin like Adobe Acrobat need to clear a hidden setting. Firefox should clear it automatically when you switch preferred viewers on the Options page, but sometimes... stuff happens.

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

(2) In the search box above the list, type or paste full_ and pause while the list is filtered

(3) If the plugin.disable_full_page_plugin_for_types preference is bolded and lists "application/pdf" and nothing else, you can right-click > Reset the preference to clear that. If it lists multiple content types, you can double-click it and edit out application/pdf from the list.

Any progress so far?

i get a blank page

No help yet

ed0505 said

i get a blank page

If you check the address bar, to the left of the PDF's URL, does Firefox display a plugin notification icon? It typically looks like a small, dark gray Lego block. (When the plugin needs updating, the icon turns red.)

If the icon appears: click it and check whether the plugin is allowed on the page and if not, allow it.

If the icon does not appear: your application handling settings file might be corrupted. To address that:

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

When you start Firefox up again, download preferences should be reset to default values. Go back to the Options page and change from the PDF Viewer to Adobe Acrobat (in Firefox) and test again. (View PDF files using Firefox’s built-in viewer)

Any improvement?

Still blank page

You can check the value of plugin.disable_full_page_plugin_for_types on the about:config page and remove application/pdf 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 check the value of pdfjs.disabled to make sure it is default (false).

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

See also:

• https://support.mozilla.org/kb/view-pdf-files-firefox-without-downloading-them
• https://support.mozilla.org/kb/disable-built-pdf-viewer-and-use-another-viewer

Since you are a person of few words, let me repeat a question:

(1) If you check the address bar, to the left of the PDF's URL, does Firefox display a plugin notification icon? It typically looks like a small, dark gray Lego block. (When the plugin needs updating, the icon turns red.)

And I have a second question:

(2) What version(s) of the plugin are you using? Please check the following:

Type or paste about:plugins in the address bar and press Enter. This should load a list of plugins with the various kinds of content they can handle.

Then use Find (Ctrl+f) to search for pdf in the page. This should take you to the first match. For example:

Adobe Acrobat

File: nppdf32.dll,nppdf32.dll Path: C:\Program Files (x86)\Adobe\Acrobat 11.0\Acrobat\browser\nppdf32.dll,C:\Program Files (x86)\Adobe\Acrobat 11.0\Acrobat\Air\nppdf32.dll Version: 11.0.14.16 State: Enabled Adobe PDF Plug-In For Firefox and Netscape 11.0.14

What does yours show?

If you repeat the find a few times, do you have a second or third Adobe plugin? If so, what are their details?