After updating to version 6.4.3 you receive an error message saying "there was a problem opening the preference file, try throwing it out and start again."

Solution:

Right-click the Starry Night application in the (C:)-->Program Files folder and choose "Run as Admin".

On Windows 8 to run as Admin see here:

https://support.simulationcurriculum.com/entries/22636776-run-as-administrator-windows-8