Hi Ananth,
This error message comes when method call is not assigned to RFC destination in ECC. Please use the below mentioned link to assign the same
SAP NetWeaver → Application Server → IDoc Interface/Application Link Enabling (ALE) → Communication → Determine RFC Destination for Method Calls
or
T-Code BD97
Also please check whether your RFC destination is working fine (i.e are you able to remote logon to the RFC destination)
T-Code SM59
