my bookmarks dissappear after the last update

Juan Ospina, If you are missing data after a Firefox update then see here: https://support.mozilla.org/en-US/kb/recover-user-data-missing-after-firefox-update

I find it unbelievable that an update (159) to the Firefox browser would destroy my bookmarks! How can this be? If I can't recover my bookmarks I will have to rebuild the bookmarks from scratch and memory in which case I will replace the Firefox browser because I won't be able to trust it anymore.

Hi nilesjo, did you try the steps in the support article linked in the reply above yours? Recover user data missing after Firefox update or reinstall