My system dual-boots between Ubuntu and Windows. I've set up a shared profile between the two operating systems. Everything works fine for normal browsing. When I add an extension from Windows, everything works fine -- the extension is visible from Windows and Ubuntu. The problem: When I add an extension from Ubuntu and restart Firefox the extension is not installed. The extension is not in the list of installed extensions. I presume there's something wrong with some value in the profile, any ideas what is incorrect?