Can't get my Bookmarks Toolbar back

A couple of extra checks can help tell whether the toolbar is just hidden or the bookmarks themselves have moved. First, make sure you are not in full-screen mode, which hides the toolbars, and try a new window to see whether the toolbar shows there. If the toolbar is visible but empty, open the bookmarks library and look in the other bookmarks folders, as items can end up there after a change. From the same library menu you can also restore a backup from a date before the change, which is worth trying if individual bookmarks are genuinely missing rather than just hidden. Finally, in customise mode, check that the bookmarks toolbar has not been moved or left with no items, and then put your most used pages back on it one at a time so you can see which step restores them.