datastax opscenter Unable to find a matching cluster for node with IP

I'm trying to configure a new OpsCenter 5.2.2 manually to a newly launched and running Cassandra Cluster 2.0.17, so I add a cluster conf file, start the OpsCenter, which then creates the CF OpsCenter, all fine. When I start the datastax agent on the first node I get this:

2015-10-29 17:25:11+0100 [] WARN: Unable to find a matching cluster for node with IP d1r1n1; the message was [u'5.2.2', u'/2122343799/conf']. This usually indicates that an OpsCenter agent is still running on an old node that was decommissioned or is part of a cluster that OpsCenter is no longer monitoring.

Seems the agent is trying to push data to OpsCenter which then in turn doesn't recognize a cluster holding this node. But why what maybe I be missing?

Just defined my cluster in /etc/opscenter/cluster/cluster.conf:

[jmx]
port = 8081

[kerberos_client_principals]

[kerberos]

[agents]

[kerberos_hostnames]

[kerberos_services]

[cassandra]
api_port = 9161
seed_hosts = d1r1n1,d1r1n2,d1r1n3,d1r1n4
conf_location = /etc/cassandra/blob.conf/cassandra.yaml
log_location = /var/log/cassandra/blob-system.log

[storage_cassandra]
api_port = 9161