Hello, Delete the FireFox from the control panel and reinstall it. if you have already done that then try the below. Try to click the "Restore Defaults" button in the Customize palette ("3-bar" Firefox menu button > Customize)

Make sure that toolbars like the "Bookmarks Toolbar" are visible.

   "3-bar" Firefox menu button > Customize > Show/Hide Toolbars
   View > Toolbars
   Tap the Alt key or press F10 to show the Menu Bar
   Right-click empty toolbar area 

Open the Customize window and set which toolbar items to display.

   "3-bar" Firefox menu button > Customize 

   check that "Bookmarks Toolbar items" is on the Bookmarks Toolbar
   if "Bookmarks Toolbar items" is not on the Bookmarks Toolbar then drag it back from the Customize palette into the Customize window to the Bookmarks Toolbar 

   if missing items are in the Customize 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 Customize palette then click the "Restore Defaults" button to restore the default toolbar setup
   https://support.mozilla.org/kb/customize-firefox-controls-buttons-and-toolbars

The restore defaults in customise is grayed out. everything else was as it should be.

You can check if you can start Firefox in Safe Mode by holding down the Shift/Options key.

• https://support.mozilla.org/kb/Safe+Mode

If you have submitted crash reports then please post the IDs of one or more recent crash reports that have a "bp-" prefix:

• bp-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx

You can find the Report ID of recent crash reports on the "Help > Troubleshooting Information" page (about:support).

• Click the "All Crash Reports" button on this page to open the about:crashes page and see all crash reports.

If necessary then you can open about: pages via the location/address bar.

See:

• http://kb.mozillazine.org/Mozilla_Crash_Reporter
• https://support.mozilla.org/kb/Mozilla+Crash+Reporter

If you can't open Firefox, see:

• http://kb.mozillazine.org/Mozilla_Crash_Reporter#Location_of_crash_reports
• http://kb.mozillazine.org/Mozilla_Crash_Reporter#Viewing_crash_reports

• https://developer.mozilla.org/How_to_get_a_stacktrace_for_a_bug_report