A security update that Apple released (2015-001) caused an issue with the authorization system for Cakewalk software on OS X. This affected customers running the Mac OS only. Z3TA+ 2 would not open unless you were within the 30 day demo period.
We have fixed this issue in the latest update, Z3TA+ 2.1.2, for OS X. The new installer can be run over an existing installation and it will fix the problem. This can also be installed on new machines without Z3TA+ 2 previously installed.
Users can visit the products list of their Cakewalk account to download and install the Z3TA+ 2.1.2 update for OS X. Windows users do not need this update.