I upgraded to Mac OS 10.10 Yosemite and something strange happened with my installations of IntelliJ IDEA. They just disappeared. I still don’t know what happened to them. When I tried to reinstall IDEA 13 Community Edition, it crashed on launch. Fortunately, my Twitter community came to my rescue. I’m sharing my experience here, just to make it easier for those who upgrade after me. I found two solutions. A Risky Solution When I reinstalled Java SE 6 and made it my system Java virtual ma...