I am having the same issue and I have experienced it more than once. The system freezes and I am able to view my work but unable to use any of the functions on the program i.e save. I am forced to quit and restart the application. Some projects I have been able to partially recover whereas others I've lost the entire piece. How can I resolve this issue? In addition, is there an option for the app to autosave after a certain period of time?