OSX may block the Makelangelo Software because it is from an "unidentified developer".

Click the apple icon in the top left, then System Preferences, then Security & Privacy. Having just tried to run Makelangelo-software*.jar, it should appear in this message.

You might need to unlock to allow security changes.

Click Open Anyways.

Your security for this version of the app should now be set forever. Next time the app updates you might need to do this again.