Occasionaly software updates with IE, Firefox, Safari, and many of the other browsers can cause problems with Adobe Reader (pdf) documents from loading and displaying.
We have found that going into your browser settings and changing how PDF documents load can fix a majority of the problems. Here is a screenshot of FireFox v.26 Under Tools, Options choose "Applications". Go find anything to do with Adobe Acrobat and Portable Document Format (PDF) in the list and change the action to "Use Adobe Reader (default)"
Each browser will have a similar area like below for you to make these changes. Click here to learn about your browser settings.