I had downloaded the .pkg extension already. I did it again a few minutes ago, still got the same problem.
Maybe it will get better with EarMaster pro6?

ear master pro 5, download version.I've got a macbook pro, 10.7.5
The software takes a little bit to start (some minutes) before giving me that error message.

I'm a new user, I just installed EarMaster Pro on my macbook, what can I do to fix this problem?
"MIDI Client Create Error - Could not create a Midi Client."
Thanks!