This could be a couple of things. If you take a look in the /lib/SDPM/partslist/VNMSH.idb? Name resolution can come into play here. Are you using DNS? Do you have anything configured in etc/hosts? If you do, make sure there isn’t a typo. If you don’t, try adding in the IP, shortname, then FQDN of the SS.
Other times you cannot connect (but you usually get a different message) it may be due to a blank/empty file named “connect” in the vnmsh directory, there is an issue with your username, or the .hostrc is not configured properly.
Hope that helps
Jay