Verifying User Authentication Credentials

If you are certain that the connection parameters are correct, verify the authentication parameters. To complete a connection, you must authenticate as a user that is known to the managed server.
Connect to the managed server through the console and check that your root password is correct. Then use that password to authenticate as the root user from your client.
If the managed server is in lockdown mode, you must authenticate using a CIM ticket obtained from vCenter Server. See for more information about using a CIM ticket to authenticate.