I have noticed a few Mac users have come upon an issue where PDF’s do not open in Safari or that they simply appear blank.¬¨‚Ć The issue is that there is an older Adobe Acrobat plug-in NPAPI-Plug-In has been installed an is no longer supported.¬¨‚Ć Even if you install a new version of Adobe Reader this older plugin remains on the¬¨‚Ć machine and browsers like Safari will attempt to use it and the users will see a blank screen.

To Fix:  Simply close Safari and then remove the plugin.  The easy way is to use spotlight search and simply type in NPAPI,  then click on show in Finder.

show in folder

Now in the list that pops up simply delete or drag to Trash any file that shows up that has npapi and the word plugin in it.

Another way to fix is to click on the Finder Smiling face,  then click on the top of the screen and choose GO | Go to Folder

In the box that pops up, type /Library/Internet Plug-Ins

gofinder

In this list that opens drag to Trash any and all files that have the characters npapi.

Screenshot of /Library/Interent Plug-Ins with older npapi plugins. Highlighted a NPAPI.plugin that needs to head to Trash.

npapi

That’s it, with these removed you can simply restart Safari Browser and PDF’s should open normally.

On a side note:  the new Firefox Version 19.0 Browser has a built in PDF viewer similar to Chrome and will open up PDF natively ignoring any plugins at all.   http://www.mozilla.org/en-US/firefox/new/