I understand that the PDF viewer in Firefox is no longer working. I have reset the application settings for the pdf file mimetype in the Firefox Application settings.

• Applications panel - Set how Firefox handles different types of files

If the default continues not to work after resetting this setting, please check out a work around:

In order to change the default reader for PDF files (to not open PDF files with Firefox's internal PDF reader), follow these steps:

1. Click the menu button and click Options (Preferences for Linux and Mac).
2. In the Options (Preferences for Linux and Mac) window, select the Applications panel.
3. In the Search field, type PDF. You should find Portable Document Format (PDF).
4. On the right hand side you should find an Action column. Use that to select your favorite PDF reader. In order to view PDF files in Firefox, choose Preview in Firefox.

Did this fix your problems? Please report back to us!

Thank you.

Hello,

I understand that I can install and select another PDF viewer - e.g. Acrobat or other to display the file in FF. I like the native PDF viewer because it is fast and doesn't have a lot of features that I don't need.

Will the native PDF viewer work in FF 36/Mac? I don't know why it would stop working just because of an update.

I run FF 36 on a Linux system and the native viewer works there.

Right, is it possible to reset the pdf viewer or to download it one more time: *https://mozilla.github.io/pdf.js/

I can confirm that it works on another computer with the same set up. I would next recommend trying another profile:

• Profile Manager - Create, remove or switch Firefox profiles

Thanks, I will just install Acrobat or some other viewer. I don't want to compile pdf.js from source. Too bad this valuable feature broke on the Mac FF update.

Does Mac OS no longer have Preview as built-in PDF viewer?

Ok... at the moment, PDF.js is working on my Mac with FF 36.

I updated to FF 36 from FF 35 again (fourth or fifth time)

First, what didn't work: 1) I installed Acrobat Reader 2) I set the NPAPI Acrobat plugin as the viewer within FF 3) This led to blank pages when clicking on PDF links and when opening PDF files from File --> Open

What worked: 1) Reselecting Preview (aka PDF.js) as the viewer 2) Going to Help --> Troubleshooting information --> Show Profile Folder in Finder 3) Exiting FF completely 4) Deleting the pluginreg.dat file 5) Restarting FF

I don't know why it worked this time. Maybe it had to do with temporarily changing the preference to another plugin-based viewer (NPAPI Acrobat) Maybe it was forcing the pluginreg.dat file to be recreated. Maybe both or neither.

For the moment, it is working and I hope it continues.

Thanks, very much for the suggestions.