This was a bit of an oversight on our part. We inadvertently made a "public build" available in the account system - which, if downloaded and run, will prompt the error you've described here (sorry about that!).
We've gone ahead and gotten this all fixed, though. If you delete the version you currently have, and log back into your account and download again (this time, you should only have a "licensed" version available), things should work for you this time around.
Sorry for any inconvenience this may have caused. If you have any other questions, or if there's anything else we can do to help out - please let us know!