I just recently updated my MBP to Yosemite. So I downloaded the latest version of Adacity and reinstalled the application. But it crashed at start up. (The icon appeared for a second on the dock then disappeared). Help!
Please see the pink panel at the top of the page and give us the three-digit Audacity version number. Make sure you have Audacity 2.1.0 from http://web.audacityteam.org/download/mac.
Also see this FAQ: http://manual.audacityteam.org/o/man/faq_installation_and_plug_ins.html#launch.
If you are seeing a message “Audacity could not find a place to store temporary files” please see https://forum.audacityteam.org/t/audacity-2-0-6-not-installing-on-mac-os-10-10-2-solved/37388/1