I am having this problem, too. It all happened after I updated my Mac to running Mac OS X Mavericks a couple days ago.
Here's some basic info of my computer for reference:
Computer: iMac 27" mid-2011
OS: Mac OS X Mavericks (10.9.0)
RAM: 8 GB
CPU: Intel Core i7 3.4 GHz.
This is what appears in the app window for Mari0 when I go to start it.
This same problem occurs when opening Order of Twilight, too.