How did you FF update? And was your O/S x86 or x64? This makes a difference as any x64 O/S will auto install FF57x64 not FF57x86. If it installed a FFx64 that could be also be why your links and bookmark have gone missing as well.

uninstall Firefox. Then Delete the Mozilla Firefox Folders in C:\Program Files and C:\Program Files(x86) Then restart system. Note: your Firefox Profile is saved. But you should make a back up before you do : *https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles *https://support.mozilla.org/en-US/kb/export-firefox-bookmarks-to-backup-or-transfer Reinstall with Current Release Firefox 57.0.2 with a Full Version Installer *https://www.mozilla.org/firefox/all/ If still issues after up and running : Create a new profile as a test to check if your current profile is causing the problem. See "Creating a profile": *https://support.mozilla.org/kb/profile-manager-create-and-remove-firefox-profiles *http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Profile_issues If the new profile works then you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over the problem. Never work with original files. *https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data *https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile *http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox Please let us know if this solved your issue or if need further assistance.