Basecamp won't start since update to 4.2.1

Hello,

since I updated my Basecamp version to 4.2.1 it does not start anymore.

OSX 10.8.4

Basecamp 4.1.2 worked. Update was automatic loaded out of Basecamp. I deinstalled it. Deinstalled the pkk file. Loaded the program through garmin web site as well as the app store. No success.

The only version that is working (and available) is Basecamp 2.1.2

1. Where can I get Basecamp 4.1.2?
2. What do I need to do to run 4.2.1?

Thanks