Which was the team experience you were disheartened with and what step you would have taken to make it better?
These are tricky questions. The interviewer wants to check whether you are actually a good team player. And someone who had a disappointing team experience can’t himself be a good team player. Avoid saying that you were disappointed with a certain experience. Describe it as a minor hiccup and then suggest the action you might have taken to avoid it.
