Problems opening PDF files on Mac with Firefox
Mozilla recently released a new version of Firefox which has caused problems with opening PDF files on websites including Blackboard. Users are either getting a missing plugin error or a blank screen when trying to open a PDF file in the browser.
If you are having these problems, in Firefox click on “Firefox” menu, then “Preferences”, go to the “Applications” tab, search for “pdf” and change the “Action” for pdf to “Always ask”. This will give you the option to save the file or open it with either Acrobat Reader or Preview.
If this does not work for you use an alternate browser such as Safari or Chrome or save the pdf file and then open it.