Should the agent or its child process encounter a terminal error, the container will stop. To automatically have Docker restart a failed container, use the --restart always switch (consult the Docker documentation for other available restart policies):

Be aware that if the external server is removed by the administrator (by deleting it from ICE Desktop settings), the container will terminate automatically and will immediately fail when restarted. This is by design to prevent an external agent from simply re-creating an external server immediately after being deleted by the administrator. As noted in the agent logs, the saved token file will need to be manually deleted from the conf/ directory before the agent tries to re-create a new external server entity.