# docker – ‘Kibana server is not ready error’ after ElasticSearch upgrade to 7.17

Upgraded Elasticsearch from 7.10 to 7.17 . After Upgrade, the ES & kibana nodes are up but when trying to access the Kibana frontend, gets error ‘Kibana server is not ready yet‘. I checked logs at \var\logs\messages\ and few similar error posts but didn’t find anything specific.
The environment is set up as a 3-node Elasticsearch cluster on linux and a single Kibana instance using docker-compose.

On executing below , gets further notification
curl -XDELETE https://<SerVerName>:Port/*kibana*

*curl: (60) Peer's certificate issuer has been marked as not trusted by the user. More details here: http://curl.haxx.se/docs/sslcerts.html curl performs SSL certificate verification by default, using a "bundle" of Certificate Authority (CA) public keys (CA certs). If the default bundle file isn't adequate, you can specify an alternate file using the --cacert option. If this HTTPS server uses a certificate signed by a CA represented in the bundle, the certificate verification probably failed due to a problem with the certificate (it might be expired, or the name might not match the domain name in the URL). If you'd like to turn off curl's verification of the certificate, use the -k (or --insecure) option.*