Hello - by 'latest version' do you mean CCC 4.0? If you still have the 3.x version that might be the issue - visit Bombich Software as already suggested.
My two Macs are still on Mavericks (wating a bit) and I have CCC 3.x on both - sent Bombich an email and the suggestion was to purchase the newest version (half price for those w/ a previous copy of CCC, i.e. about $20) and run on Mavericks - presumably installing Yosemite whould find a workable copy of CCC - others who have done these steps will hopefully 'chime in' w/ comments - good luck. Dave