If you close the select new duplicants screen (without actually selecting a new duplicant) by exiting out of with the escape key, the 'new duplicant' music doesn't stop. Going to the screen again will result in an immediate client crash.
If you close the new duplicant selection screen using the little x in the upper right, this crash will not occur.
Steps to Reproduce
You are notified that new duplicants arrive. You click the portal and go to the select new duplicants screen. The music changes. Hit escape to exit the screen. The music remains however and does not stop. Clicking the portal and attempting to enter the duplicant selection screen again will result in a client crash. If however you close the new duplicant selection screen with the little x in the upper right of the window instead of using the escape key, this crash will not occur. It only occurs if you hit the escape key to exit out of it.
This issue has been fixed in either a future version or updated in a previous version.