I am having the same problem! I need to use my TonePortKB37 on my macbook air, but under Yosemite I can't install it, I get the same message about being unable to install on Macintosh HD. Oddly enough I can get Gearbox 3.0 (That came on a CD originally with the hardware) to install on Yosemite, but it can't see my KB37! When do you think we will get an update? Surely its just one line of code?