Could you describe the sequence of events leading up to this problem?

Do you now have a partial set of bookmarks or none at all?

Your "More System Details" shows 3 versions of the Shockwave Flash (Flash player) plugin. To avoid conflicts, please disabled the older versions on the Add-ons page. Either:

• Ctrl+Shift+a
• orange Firefox button (or Tools menu) > Add-ons

In the left column, click Plugins. Look for "Shockwave Flash" and change the older versions to "Never Activate".

Or you can use Adobe's uninstaller and reinstall just the latest version.

Are you still using your previous default Firefox profile folder?

• https://support.mozilla.org/kb/Recovering+important+data+from+an+old+profile
• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

You can check for problems with the places.sqlite database file in the Firefox profile folder.

• http://kb.mozillazine.org/Bookmarks_history_and_toolbar_buttons_not_working_-_Firefox
• https://support.mozilla.org/kb/Bookmarks+not+saved#w_fix-the-bookmarks-file

• Places Maintenance https://addons.mozilla.org/firefox/addon/places-maintenance/

These can't get your data back, but will help in the future. These add-ons can be a great help by backing up and restoring Firefox

FEBE (Firefox Environment Backup Extension) {web link} FEBE allows you to quickly and easily backup your Firefox extensions, history, passwords, and more. In fact, it goes beyond just backing up -- It will actually rebuild your saved files individually into installable .xpi files. It will also make backup of files that you choose.

OPIE {web link} Import/Export extension preferences