Whenever the application crashes, you need to delete its preferences, as they become corrupted and that can cause further crashes.
To delete preferences, hold down command and option while starting the application and click Delete Custom Settings. The application will start with default settings and open an "Untitled" library. Adjust the settings, reopen the library you were working, and see how it works now.
If the problem persists:
1) try in a different project, and in a new library; same problem?
2) Please run Etrecheck and post its full report here.
Use the "additional text" button and paste the report into the text box.