Hi, sorry to hear about this problem. Some bookmark problems can be resolved by doing a regular shutdown and restart of Windows 10 -- this frees up file locks, completes any pending updates, and hopefully resolves any transitory permission issues. Are you missing the Bookmarks Toolbar that displays below the main toolbar, or are the bookmarks missing in other lists as well, such as the Bookmarks Sidebar (Ctrl+B)? To redisplay the Bookmarks Toolbar, see: [[Bookmarks Toolbar - Display your favorite websites at the top of the Firefox window]]. ''If all of your data is missing:'' Could you check whether your stuff is available in a different profile, as follows: '''Profile Manager Page''' Inside Firefox, type or paste '''about:profiles''' in the address bar and press Enter/Return to load it. This page should list at least one profile and could list many. (Each profile has two folders and one or more buttons. Do not use any Remove buttons!) The profile that Firefox is currently using will have this: '''This is the profile in use and it cannot be deleted.''' Do you have any other profiles listed on this page? If so, you can check whether it is the one you were using recently by clicking its '''Launch profile in new browser''' button. If it isn't what you want, simply close that new window. If it IS what you want, back on the about:profiles page, click the '''Set as default profile''' button for that profile so Firefox uses it automatically at the next startup. Any progress so far?