Make sure that you still have the Bookmarks Toolbar items of the Bookmarks Toolbar.

Make sure that toolbars like the "Navigation Toolbar" and the "Bookmarks Toolbar" are visible: "View > Toolbars"

• Open the Customize window via "View > Toolbars > Customize"

• Check that the "Bookmarks Toolbar items" is on the Bookmarks Toolbar
• If the "Bookmarks Toolbar items" is not on the Bookmarks Toolbar then drag it back from the toolbar palette in the customize window to the Bookmarks Toolbar

• If missing items are in the toolbar palette then drag them back from the Customize window on the toolbar
• If you do not see an item on a toolbar and in the toolbar palette then click the "Restore Default Set" button to restore the default toolbar set up

• http://kb.mozillazine.org/Toolbar_customization

Another possible cause is a problem with the file places.sqlite that stores the bookmarks and the history.

• http://kb.mozillazine.org/Bookmarks_history_and_toolbar_buttons_not_working_-_Firefox
• https://support.mozilla.org/kb/Bookmarks+not+saved#w_fix-the-bookmarks-file

You can also try to repair the places database with this extension:

• https://addons.mozilla.org/firefox/addon/places-maintenance/

Hi!

I have tried all of these things. Firefox behavior has been incredibly erratic for me. My Options settings seem to change at any time for no reason. I have made a copy of my "good" profile and have to use it 2-3 times each day. If I can't get FF to stop doing this, I will have to consider a different browser.

hb

Which security software (firewall, anti-virus) do you have?

Some security software has virtualization features that can cause problems by protecting and restoring files in the Firefox profile folder.
Cleanup software also can cause files to get corrupted.

I use Norton Internet Security, and have for a long time.