As you can see in the image, the spinning wheel of death occurs when going to Patch for Dmx and Midi>Midi Input. Right when I click on Midi input the software freezes for a sec then I get the wheel.
I tried downloading this software on another mac and everything worked fine. The only difference between the two macs is the one freezing is running mavericks and the one not freezing is running Lion 10.7.5.
Hope this helps. I will test on more macs to see if I can repeat this process and will get back to you on results.