For the download problem, see if this article is helpful: [[What to do if you can't download or save files]] If the [[Refresh Firefox - reset add-ons and settings|Refresh Firefox]] button is missing from the about:support [[Use the Troubleshooting Information page to help fix Firefox issues|Troubleshooting information page]], it's a [https://bugzilla.mozilla.org/show_bug.cgi?id=1928138 known issue] that happens after creating another profile in the new [[Manage Firefox profiles]] system. Hopefully it will be fixed soon but if you really need to reset Firefox, there's a "Refresh Firefox" button in the uninstaller. See [[Uninstall Firefox from your computer]]. '''Warning:''' using the Refresh Firefox option in the uninstaller after you have created other profiles in the new [[Manage Firefox profiles]] system can cause Firefox to lose access to the other profiles, as explained here: https://support.mozilla.org/en-US/questions/1548459#answer-1781449