Good to hear! =)
The short Payment ID has been around for a while, but the older is still supported. Unfortunately polo don't support the short one yet. But you could still use the integrated address generated by the GUI if you need to assign the transaction from polo to a payment ID in your wallet. More info: https://getmonero.org/knowledge-base/moneropedia/paymentid

Note: Apple has ended their support for os x 10.9. Even though my build works for you I can't promise you that the official build will.