To operate, Aurora requires a valid license which you can purchase at the oneperiodic.com web site. Upon purchase, you will be sent an email which has the license. Simply enter the license when prompted or select Aurora > Licensing and enter the license.
Aurora has a 14 day evaluation period built in, during which you can use all features of Aurora with no exception. After that period ends, Aurora won't set up alarms anymore unless you purchase a valid license.