Hi @sergeiakhmetov, it's nice to see you again in our Community Forums. I am sorry for the delayed response.
I am sorry to hear your Fitbit app is crashing when you try to see sleep phases. Thanks for trying to resolve this, I appreciate the additional details and I am here to help. I recommend doing the following:
Keep me posted on the outcome.
Want to discuss ways to increase your activity? Visit Get Moving in the Lifestyle Discussion Forum.