Issues backing up Server 2012R2

We are running BackupExec 2008R2 on a server running Server 2008R2.  The environment is all Server 2008R2 bar one server that is 2012R2.

The agent is installed and services running, however we constantly get the error:

V-79-57344-33932 Unable to attach to a resource. Ensure that the selected resource exists and is online, and then try again. If the server or resource no longer exists, remove it from the selections

We have uninstalled and reinstalled the agent via push, but still no joy.

Any suggestions?

This is a physical machine with 12gb ram and that is hardly used.

thanks

Olly