java.lang.NullPointerException

Hello,
We can send idoc successfully from SAP system to another SAP system with SAP BC. But when we are trying to send idoc from sap to BC and save the file locally in to ftp://127.0.0.1/admin/response folder (see screenshot) we are getting Rolled-back error in SAP BC server and in sm58 java.lang.NullPointerException. Could you please let us know why this happens? Thanks for your help,

esimov

[screenshot]

problem solved with Transport >B2B Service!