statusReason 
  A short description of the reason the stream session is in ERROR status or TERMINATED status.
ERROR status reasons:
applicationLogS3DestinationError: Could not write the application log to the Amazon S3 bucket that is configured for the streaming application. Make sure the bucket still exists.internalError: An internal service error occurred. Start a new stream session to continue streaming.invalidSignalRequest: The WebRTC signal request that was sent is not valid. When starting or reconnecting to a stream session, usegenerateSignalRequestin the Amazon GameLift Streams Web SDK to generate a new signal request.placementTimeout: Amazon GameLift Streams could not find available stream capacity to start a stream session. Increase the stream capacity in the stream group or wait until capacity becomes available.
TERMINATED status reasons:
apiTerminated: The stream session was terminated by an API call to TerminateStreamSession.applicationExit: The streaming application exited or crashed. The stream session was terminated because the application is no longer running.connectionTimeout: The stream session was terminated because the client failed to connect within the connection timeout period specified byConnectionTimeoutSeconds.idleTimeout: The stream session was terminated because it exceeded the idle timeout period of 60 minutes with no user input activity.maxSessionLengthTimeout: The stream session was terminated because it exceeded the maximum session length timeout period specified bySessionLengthSeconds.reconnectionTimeout: The stream session was terminated because the client failed to reconnect within the reconnection timeout period specified byConnectionTimeoutSecondsafter losing connection.