Please keep in mind that any pop-up blocker you may have running can prevent the file from downloading. In most cases, your pop-up blocker can be temporarily disabled by holding down the "Ctrl" or sometimes the "Shift" key while clicking on the document's link.
After waiting a minute or so, your browser will occasionally fail to open the file and return only a blank screen. This can be due to your browser settings not dealing with the PDF file properly. This can sometimes be resolved by entering the Edit menu in Adobe, clicking on Preferences, followed by Internet, and then unchecking "Display PDF in browser".
A good source of information would be Adobe's Support Knowledgebase. Troubleshooting categories including downloading and installing Acrobat Reader, printing problems, and configuring your web browser to properly display PDF files are included on their support page.
If you need assistance in finding the correct literature for your engine, please visit our Obtaining Engine Manuals/Literature FAQ.