Hi, I work in tech support, and one of the user's I work with received a new computer. She has to open hundreds of pdf files a day for her job role. On her old computer, when clicking on a pdf file in Firefox, a new tab would open very briefly, and then close, taking her back to the original website she was on, with the standard "Open With or Save File" window. On the new computer, when clicking on a pdf file, the new (blank) tab stays open until she manually closes it. I feel like there should be an easy way to prevent that new tab from staying open, but I have toggled every setting in Firefox that is available to me regarding opening new tab or windows, and what to do when opening pdf files, but the new tab / window always stays open. I was going to start toggling the settings in about:config, but wanted to crowd source ideas before making some potentially damaging changes. Any help would be greatly appreciated on this matter. I know that her old computer would have been updated to FF 52 from an older version, and I noticed yet some of the settings were the same as older versions (i.e. the menu bar was still active) where the new computer had a fresh install of FF 52. Thanks, David