Zcs 5.0.9 server error.

In the admin console of zimbra when I click Mail Queues and Certificates,I'm getting the following weird error:

Server error encountered Message: system failure: server myserver.com
zimbraRemoteManagementPrivateKeyPath (/opt/zimbra/.ssh/zimbra_identity) 
is not readable Error code: service.FAILURE Method: GetServerNIfsRequest 
could anybody on the forum give a hand on this....