According to the information I've found on the Brother's website, the latest version of NewSoft CD Labeler posted and available for download is compatible with OSX 10.8 or LATER. "Later" means that it should work with the latest version of OSX as well, but it's not guaranteed.
Try downloading the application they recommend to see if it installs and works properly, because you might have an old version that's incompatible with the latest OSX iterations.