Hi talrob, do you mean clicking a link in a web page to a PDF, Firefox just sits there? Or is the link coming from outside Firefox? Or is it a PDF already saved to your system? Could you check your PDF setting and maybe experiment with a different one, for example, if Preview in Firefox isn't working, how about Save File? Or vice versa: [[View PDF files in Firefox]] Note: Firefox has a feature to browse for a program to open PDFs. Don't use that feature to point Firefox back to itself or you will get this problem: [[Firefox repeatedly opens empty tabs or windows after you click on a link]].