I recently upgraded and updated my Mosquitto Broker to 1.4.15 on Raspberry-pi3. It works as expected. However, every time I enable and set cleansession to true in the Mosquitto.Conf file, Mosquitto broker refuses to start. As soon as I comment out or disable cleansession, Mosquitto broker starts up immediately by its service. The reason I need to set this to true is because I want the Mosquitto Broker to clean up any disconnected clients' session. So that the same client can reconnect again to the broker. Am I doing this right? or Is there another Mosquitto Broker's feature that I can use in place of cleansession?
The cleansession flag in the mosquitto.conf is to control what options mosquitto uses when it connects to remote brokers as a client when setting up a bridge.
If you want your clients to connect with a clean session then you need to set that option in your client library when setting up the connection not on the broker.