Hi, I've uninstalled an add-on but it is still active in the browser. The feature of this add-on is to ask you, using pop-up window, for your password at the startup of Fiferox to open the browser and, sort of speaking, to "let you in" the browser. But I don't need this feature any more, so I've removed the add-on using about:addons tab (so far so good). But even after the removal, the prompt window keeps popping up. I've tried to Refresh Firefox, but it haven't solved it. The safe-mode with blocked add-ons helps during the safe-mode session, but I need a permanent solution and ability to use other add-ons. I'm not exactly sure of the exact name of the add-on as I have been using several different startup password add-ons during previous months (never simultaneously). I think it was the StartupMaster https://addons.mozilla.org/en-US/firefox/addon/startupmaster/ But now, I've been updated to Firefox Quantum 58.0.2, so there's no option to install StartUpMaster back and try to remove it again, because the current version of StartUpMaster doesn't support the current version of Firefox :/ The pop-up window appears once after opening FF and I am able to close/skip it and the FF works fine. And no, no such or similar add-on is listed among the installed add-ons in my Firefox. So there is a pop-up window with prompt everytime I start Firefox and it's annoying. I haven't found any add-on uninstaller compatible with Firefox Quantum and downgrade from Quantum to find compatible version of FF and StartUpMaster add-on seems to be not possible. Any ideas how to remove already uninstalled add-on from the browser, eg. registry tweaks etc.? Image of the prompt window (FF started in Refresh Firefox mode): https://ibb.co/nPjxVn Current list of installed add-ons: https://ibb.co/chkRO7 Thanks a lot.