This one, ignore the Blue Star and go to the next one : https://support.mozilla.org/en-US/kb/how-do-i-delete-bookmark

Or mouse to the top of the Browser and Right Click and turn on the Menu Bar, Delete/Edit from Bookmarks Title.

Or can turn it on from Customize mouse to bottom to Toolbars and turn on Menu Bar. The Bookmarks tool Bar is for dragging and dropping bookmarks to for fast use and or create folders of like stuff.

Please let us know if this solved your issue or if need further assistance.

I tried them all and none worked. Occasionally, if I reinstall Firefox, I can delete one item - and then no more. I have a huge number of bookmarks that are duplicates and many that are useless.

Just noticed I cannot rearrange the bookmarks on the ToolBar either.

If you use Sync then best is to disconnect Sync temporarily during troubleshooting.

You can check for problems with the places.sqlite database (bookmarks and history) in the Firefox profile folder.

• use "Verify Integrity" on the "Help -> Troubleshooting Information" (about:support) page

See also:

• https://support.mozilla.org/en-US/kb/Bookmarks+not+saved#w_fix-the-bookmarks-file

If "Verify Integrity" on the "Help -> Troubleshooting Information" (about:support) page cannot repair places.sqlite then remove all places.sqlite files in the Firefox profile folder. Firefox will rebuild places.sqlite and restore the bookmarks from a recent JSON backup in the bookmarkbackups folder.

• keep a backup copy of places.sqlite in case a new places.sqlite database has to be created

You can use the button on the "Help -> Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page.

• Help -> Troubleshooting Information -> Profile Directory:
  Windows: Show Folder; Linux: Open Directory; Mac: Show in Finder
• https://support.mozilla.org/en-US/kb/Profiles