Today i realised that in SAPGUI 740 along with NWBC we no longer require to edit services file "C:\Windows\System32\drivers\etc\services" to create logon group connection.
in fact it is not trying to collect details from service file and giving me message error:hostname "'MSGhost" not reached then i tried adding message server port with : seperation next to message server host, it worked...
hope info will be usefull to someone