When attempting to start a session via the AWS Systems Manager, I received the following error message "The SSM Agent version installed on this instance doesn’t support streaming logs to CloudWatch. Either update the SSM Agent to the latest version, or disable the streaming logs option in your preferences."
I experienced the same issue and solved it by updating the agent: Open the AWS Systems Manager console at https://console.aws.amazon.com/systems-manager/ . In the navigation pane, choose Managed instances. Choose Agent auto update.