"Empty document Found" error while sending a text file

Below is the error I'm getting while I'm trying to send a txt file using a fiel adapter.

Channel FILE_TLE_Sender_SalesOrder_CC: Converted complete file content to XML format.

Channel FILE_TLE_Sender_SalesOrder_CC: Empty document found - proceed without sending message.

File "/data/TLE/XS1/inbound/850/Test_SalesOrder_3064_12-15-10.txt" deleted after processing.

On the Communication Channel this is what I have:

Recordset Name: DOCUMENT_ROOT

Recordset Structure: DOC_HEADER,1,PO_HEADER,1,TAX,,FREIGHT,,SPECIAL_SHIP,,DOCUMENT_NOTE,,SHIP_TO_ADDRESS,,PRODUCT,,LINE_SHIP,,LINE_ITEM_NOTE,,ASSOC_LINE,,ORDER_MEMO,,DOC_TRAILER,1

Key Field Name: keyfield

DOC_HEADER.fieldNames Value: keyfield,Source_System,Source_SUB_System,Source_Doc_Type,Source_Doc_Gen_Date,Source_Doc_Gen_Time,Source_Company,Source_Division,Source_Party_ID,Source_Ship_Location,Source_Sell_Location,Event_Name,Application_Program_File,Application_Program_Name,Destination_System,Destination_SUB_System,Destination_DOC_Type,Destination_Company,Destination_Division,Destination_Party_ID,Destination_Ship_Location,Destination_Sell_Location,Interchange_Control_Number,Group_Control_Number,Document_Control_Number,Date_Translated,Time_Translated,Primary_Key

DOC_HEADER.fieldFixedLengths Value: 30,30,30,30,10,4,30,15,30,20,20,8,30,30,30,30,30,30,15,30,20,20,10,10,10,10,4,30

DOC_HEADER.keyFieldValue Value: DOC_HEADER

DOC_HEADER.lastFieldsOptional Value: YES

DOC_HEADER.endSeparator Value: 'nl'

Then I have same pattern for PO_HEADER, TAX and so on....

Can someone tell me why this error is happening? I'm using the same exact parameters in another XI environment and there's no error there.