Session BGP Router '[{#BGP_ROUTER_NAME}]', AS '[{#BGP_PEER_REMOTE_AS}]', peer '[{#BGP_PEER_REMOTE_ADDR}]' is down, check BGP configuration.
For information on checking BGP configuration, see: https://www.juniper.net/documentation/us/en/software/junos/bgp/topics/topic-map/troubleshooting-bgp-sessions.html.