Originally Posted by JediMeister
Most of the issues I have seen are caused by the Adobe PDF plugin overriding the native Preview/Safari interaction. Removing from the /Library/Internet Plug-ins folder the PDF Viewer plugin and then restarting the computer should resolve the issue.
I think this might be my issue, but I don't see a PDF Viewer plugin in the /Library/Internet Plug-ins folder.
I downloaded Adobe reader because the one site won't let me proceed to the PDF until I did. After I got what I needed, I deleted Adobe because I prefer to use Preview. I suspect that's what happened to the PDF Viewer Plug-in, but I am not sure now how to get it back.