If you have problems with importing the IE Favorites in Firefox then export the Favorites in IE to an HTML file and import that file in the Firefox Bookmarks Manager. That way you also preserve any sorting that you may have done in IE with the Favorites.

• Export the favorites in IE to an HTML file (bookmarks.html): File > Import and Export
• Import the HTML file in Firefox: Bookmarks > Show All Bookmarks > Import & Backup > Import HTML: From File

See also:

• http://kb.mozillazine.org/Import_bookmarks ("Import from another browser" and "Import from file")

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

Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of the extensions is causing the problem (switch to the DEFAULT theme: Firefox (Tools) > Add-ons > Appearance/Themes).

• Don't make any changes on the Safe mode start window.
• https://support.mozilla.com/kb/Safe+Mode

Sorry - it does not work by saving the favourites and import them. The problem is the script that again and again stops firefox. This script also blocks any trial to erase browsing history, cookies etc

Script name: chrome://browser/content/browser.js:3502