Mozilla released an emergency update to Firefox 35 on January 26, 2015 with Firefox 35.0.1. There are several fixes including for startup crash with this release. See the release notes for full details. Users may be prompted to update to the newest release (35.0.1) of Firefox or can do so manually within Firefox by going to Help > About Firefox and following the update prompts. Users may also manually download and install the newest Firefox update (35.0.1 via the getfirefox.com site. The next scheduled update for Firefox is February 24th, 2015 with Firefox 36.

“Firefox 35 has been pushed to the Stable channel recently by Mozilla and while the majority of users did not notice any incompatibilities or issues, some users noticed that one or multiple of installed browser add-ons stopped working suddenly. …” Source: gHacks Tech News Details 

Mozilla released an update to Firefox on January 13, 2015 with Firefox 35. There are several new features and fixes for this release and these can be viewed in the release notes. Users may be prompted to update to the newest release (35.0) of Firefox or can do so manually within Firefox by going to Help > About Firefox and following the update prompts. Users may also manually download and install the newest Firefox update (34.5 via the getfirefox.com site. The next scheduled update for Firefox is February 24th, 2015 with Firefox 36.