Areas to check for this error message:

1. check the 'process list' on the unix machine,
   and make sure PCNFSD daemon is running.
   
2. check the 'hosts' file on the unix machine, and
   make sure the IP_address of the windows system
   is in it.
   
3. sometimes, problems like 'out of license' or
   'license expired' will cause the error message to come up.