As you may have noticed, Astah 6.7 requires OS X Lion 10.7.5 or later and no longer supports Snow Leopard. This is because Astah is moving to Java 7 after receiving Oracle’s news of End of Public Updates of Java 6 and Oracle is supporting Java 7 only on Mac OS X 10.7 and above.
If you are using the Snow Leopard, please use the Astah 6.6.4 which is the latest version that can work on Snow Leopard.
– Astah Professional 6.6.4 (Download / Release Note)
– Astah Community 6.6.4 (Download / Release Note)
Thank you very much for your understanding.