Hi Naren, sorry for the late reply.

That seems to be a problem with the Salesforce REST component. It was created by importing the Salesforce schema of their trial version. It could be different for other editions, and I think you can even customize the schema to your needs.

Go inside the SalesforceREST module, and search for MiddleName and you'll find it inside the LeadFields action. This is a list of fields that should be retrieved from Salesforce when querying leads. Remove the MiddleName and check if that solves your problem.

Thanks.