Tried all of the suggestions here but none of them work: https://support.mozilla.org/en-US/questions/776649 We've cleared cache, cleared cookies, cleared temp internet files, updated the Adobe Plugin for Firefox, Updated Java, tried turning off windows firewall, turned off Avast Anti-Virus, confirmed pop-ups are turned on. I also changed the Enable Java Script option in the Content tab by clicking on the "Advanced" button to allow scripts to Move or resize windows, Raise or lower windows, and Disable or replace context menus. Last thing I tried...went to Options dialog, selected "Applications" and made sure that the "Adobe Acrobat Document (application/pdf)" is set to a valid application. Suggestions? Thanks!