Safari 7 and 6.1 block PDFs | Acrobat, Reader

On the first attempt to view a PDF on a new domain or website in Safari 6.1 and 7 (delivered with Mac OS X Mavericks 10.9), the browser window is gray or blank. It displays the alert: "Blocked Plug-in."

The latest versions of Safari use a new plug-in manager for enabling and disabling plug-ins on a global or per site basis. The Acrobat and Reader PDF viewer plug-ins are not trusted by default until you actively trust the plug-in globally, or for each website.

Solution: Trust the PDF plug-in

Trust the PDF plug-in globally

1. Choose Safari > Preferences > Security > Manage Website Settings. 
2. From the left panel, choose Adobe Reader or Adobe Acrobat.
3. In the When visiting other websites pop-up menu, choose Allow Always. 

Trust the PDF plug-in on a per-site basis

For each domain or website on which the "Blocked Plug-in" message appears:

1. Click the "Blocked" message.  
2. When the Trust dialog appears, choose Trust.