Hello, I have not been able to view web based PDFs in a long time and I am so frustrated! I am trying to follow the instructions on the following Mozilla article: https://support.mozilla.org/en-US/kb/view-pdf-files-firefox-without-downloading-them I installed the Schubert plug in. It was greyed out and a warning said I could not use it because Mac could not determine the software maker. I then changed security settings to allow software non-Mac and non identified designer. It is still greyed out (after restarting the computer) and won't let me select the plug in under preferences/applications/PDF (choose other). Help please! I need to be able to download pdf forms for my small business and this is really holding me back.