Could be a problem with the favicons.sqlite in the profile folder that stores favicons.

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

You can check for problems with the places.sqlite and favicons.sqlite files in the Firefox profile folder.

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

In case errors are reported with "Verify Integrity" close and restart Firefox and retry.

If "Verify Integrity" cannot repair the favicon database then try to remove favicons.sqlite in the profile folder with Firefox closed. You need to visit (click) a bookmark to make Firefox retrieve the favicon. If this didn't help then rename/remove places.sqlite as well. 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
• http://kb.mozillazine.org/Profile_folder_-_Firefox

See also:

• https://support.mozilla.org/en-US/kb/Bookmarks+not+saved#w_fix-the-bookmarks-file
• https://support.mozilla.org/en-US/kb/fix-bookmarks-and-history-will-not-be-functional

In order - I tried clicking the "Verify Integrity" button - and no fix. Next - I renamed the favicons.splite file - (I renamed to OLD.favicons.splite ) that seems to have fixed things. As I go back to sites in my menus - it recaptures the current favicon files from the sites and displays correctly, now.

Thank you!

I had a similar problem but less global than RexSmith70's. I had just two wrong favicons, for Google Docs and Google Drive. Verify Integrity didn't do anything, but deleting favicons.sqlite fixed the problem. Thanks, cor-el.

Yeah. I had this problem for a long time. I ran some queries on the sqlite tables, and tried the suggestion in other places to delete specific or all of the favicon rows before finally just removing the file. To me it looked like the ids in the tables before I deleted the file were just too high for them to work. One of them was 47,357,795,150,914. Seems like that is 10x the limit for unsigned 16 bit integer. Another column had numbers like 4,176,269,289, which is very close to that unsigned 16 bit max as well. So perhaps some part of the code that uses them are munging that number and getting the wrong icon. I have no idea how they got that high. This is definitely a bug in Firefox. Please fix it.