Type about:customizing<enter> in the address bar. Look for Show / Hide Toolbars at the bottom left.

There is also a Restore Defaults button at the bottom middle.

As a starting point, could you make sure your bookmarks toolbar is set up normally?

Check the toolbar list and make sure the Bookmarks Toolbar is turned on:

• right-click a blank spot on the tab bar (or the "+" button)
• tap the Alt key to activate the classic menu bar > View > Toolbars
• in Customize mode > Show/Hide Toolbars (see: Customize Firefox controls, buttons and toolbars)

If it doesn't have a checkmark, click Bookmarks Toolbar.

If the bar is displayed but blank, try using the Customize feature to verify that the "Bookmark Toolbar Items" control is at the left end of the bar as it should be. See this article for how to open the Customize tab: Customize Firefox controls, buttons and toolbars. If the left-most item on the Bookmarks Toolbar is not Bookmarks Toolbar Items, click the Restore Defaults button at the bottom of the Customize tab and see whether that fixes it.

Thanks. I did what you suggested and I think I have a more serious problem. When I open the Customize feature I get a blank screen with no options.

Hmm, Customize shouldn't be blank.

How did you get to this point that you lost your bookmarks? Was there some kind of severe crash? Did some new software install coincide with the problem, either a Firefox update or something else?

Start Firefox in Safe Mode {web Link} by holding down the <Shift>
(Mac=Options) key, and then starting Firefox. A small dialog should appear. Click Start In Safe Mode (not Refresh).

Is the problem still there?

Thanks. I have the same problems in Safe Mode

I recall installing a Firefox update last week but the problem didn't appear until yesterday, I have had no system crashes.

Let’s do a full clean re-install; Download Firefox For All languages And Systems {web link} Save the file. Then Close Firefox.

Using your file browser, open the Programs Folder on your computer.

Windows: C:\Program Files C:\Program Files (x86) Mac: Open the "Applications" folder.
https://support.mozilla.org/en-US/kb/how-download-and-install-firefox-mac Linux: Check your user manual.

Do Not remove the profiles folder.

Look for, and rename any Mozilla or Firefox program folders by adding .old to them. Do not rename the Mozilla Thunderbird folder.

After rebooting the computer, run a registry scanner. Then run the installer. If all goes well, remove the OLD folders when you are done.

If there is a problem, start your Computer in safe mode and try again.

Starting The Computer In Safe Mode;
Free Online Encyclopedia

Thank you. Sorry for the late response. I followed your suggestion up to the registry scanner. I do not know how to do this.

I omitted to state that I am using Windows

A registry scanner scans the registry for bad entries and removes them.

Go ahead with the install.

I installed a new version of Firefox, cleaned the registry and started Firefox. It started with three tabs. On the first tab I tried to sign onto to Firefox but Firefox seemed to go into a loop. On another tab I brought up the Customize screen but it came up blank as before. I terminated Firefox and started it up again using "Run as Administrator". This time I got only one tab. I brought up the Customize screen and it came up with options. I clicked on "Show/Hide Toolbars/ Bookmarks Toolbar" and they were displayed. I then terminated Firefox, restarted my laptop and opened Fireox normally. My bookmarks Toolbar was displayed.

Thanks for your help