Another user recently reported something similar <blockquote> If I start Firefox after a complete exit it actually show the bookmarks toolbar for just a second and then it's gone. If I check my Bookmarks and do a 'Show All' I can find all the bookmarks in there, even a seperate section for the Bookmarks Toolbar. </blockquote> We tried some of the obvious things, which I will mention, but in the end the user completely removed Firefox and all data, reinstalled, and used Sync to recover data, so we didn't get a specific explanation. '''I do not recommend jumping that that approach''' until we have tried a few less drastic things. These are some of the options: (1) Replace Firefox's program files in case they got damaged during the update (a "clean reinstall") (2) Remove the layout dimensions file (xulstore.json), then turn the Bookmarks Toolbar back on (3) Repair the Places database (4) Remove the Places database and have Firefox generate a new one from a bookmarks backup (you lose your history) '''(1) Clean Reinstall''' We use this name, but it's not about removing your settings, it's about making sure the program files are clean (no inconsistent or alien code files). As described below, this process does not disturb your existing settings. It's not essential to uninstall Firefox, but you can if you like, saying No to any request about removing personal data. It only takes a few minutes. (A) Download a fresh installer for Firefox to a convenient location: https://www.mozilla.org/firefox/all/ (B) Exit out of Firefox (if applicable). ''If you use '''Microsoft Office''', please change your default browser to Internet Explorer before the next step.'' (C) Using Windows Explorer/My Computer (hold down the Windows key and press E), right-click > rename the program folder as follows (you might have one or both): C:\Program Files (x86)\Mozilla Firefox =to=> C:\Program Files (x86)\OldFirefox C:\Program Files\Mozilla Firefox =to=> C:\Program Files\OldFirefox (D) Run the installer you downloaded in step (A). It should automatically connect to your existing settings. Any improvement? '''(2) The xulstore.json File''' Sometimes the settings file that stores various user interface dimensions becomes corrupted with nonsensical values. You can rename the file and have Firefox rebuild it. Here's how: Open your current Firefox settings (AKA Firefox profile) folder using either * "3-bar" menu button > "?" Help > Troubleshooting Information * (menu bar) Help > Troubleshooting Information * type or paste about:support in the address bar and press Enter In the first table on the page, on the Profile Folder row, click the "Open Folder" button. This should launch a new window listing various files and folders in Windows Explorer. Leaving that window open, switch back to Firefox and Exit, either: * "3-bar" menu button > Exit * (menu bar) File > Exit Pause while Firefox finishes its cleanup, then rename '''xulstore.json''' to something like xulstore.old. If you see a file named localstore.rdf, rename that one to localstore.old. Start Firefox back up again. ''That mini-reset will hide the bookmarks toolbar.'' You can use one of these methods to show the toolbar list and select it there: * right-click (on Mac Ctrl+click) a blank spot on the tab bar (or the "+" button) * (menu bar) View > Toolbars<br><em>On Windows, tap the Alt key to activate the menu bar temporarily.</em> * in Customize mode > Toolbars button (see: [[Customize Firefox controls, buttons and toolbars]]) To turn on the Bookmarks Toolbar, click it on the list. Does it reappear and stick around? '''(3) Repair Places Database''' The Troubleshooting Information page has a "Verify Integrity button to do a little light maintenance on the Places database (where bookmarks and history are stored). You can open that using either * "3-bar" menu button > "?" Help > Troubleshooting Information * (menu bar) Help > Troubleshooting Information * type or paste about:support in the address bar and press Enter Then scroll way down or use Find to search for ''Integrity'' in the Places Database section. At first, nothing will seem to happen, but then several seconds after clicking the button Firefox should report some diagnostic results below it. Please copy/paste the results somewhere safe, then exit/restart Firefox to see whether it helped. '''(4) Generate a new Places database''' I suggest making a couple backups for safety. Firefox supports two different formats, and it's best to create both: * JSON "backup" format: [[Restore bookmarks from backup or move them to another computer]] * HTML "export" format: [[Export Firefox bookmarks to an HTML file to back up or transfer bookmarks]] Then see the steps in this article: [[Fix "The bookmarks and history system will not be functional" error message]]. Firefox should restore a bookmark backup automatically. If it does not, you can try restoring the files you created manually: * JSON format: [[Restore bookmarks from backup or move them to another computer]] (use "Choose File" to access your backup) * HTML file: [[Import Bookmarks from an HTML file]] Finally, exit/restart Firefox to see whether it helped.