Basically I have followed the instructions here
But when I go to couchbase to setup the replication i get:

but I know it is there because

The machines can ping each other and no firewalls etc…..
I have found the following error in the log for elaticsearch every time i hit replicate in couchbase.

I am not sure what this means but….
Any pointers would be appreciated
Kindest Regards
Robin
Edit
Ps: lastest version of both couchbase and elasticsearch from today and running ubuntu server 12.04 LTS
I think that the CouchBase plugin has not been released yet for Elasticsearch 0.20.x but only for 0.19.x.
I think this is your issue here.
So try switching to a 0.19.9 ES version or wait for the next release of the CouchBase plugin.