From the syslog translator tool on the NetApp support site:
This event is issued when the appliance can not issue a network lock manager (NLM) callback to the client via UDP. The specified version of NLM is not registered with the client's portmapper daemon.
Make sure the specified version of the network lock manager is registered with the client's portmapper daemon. Please refer to the client's documentation for details on how to manage the NLM on the client.