How To Fix MG101 - Session &: first transaction does not begin with header record

SAP Error Message - Details

• Message type: E = Error

• Message class: MG - Batch input: material master

• Message number: 101

• Message text: Session &: first transaction does not begin with header record

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message MG101 - Session &: first transaction does not begin with header record ?

  The SAP error message MG101 indicates that there is an issue with the data being processed in a session, specifically that the first transaction in the session does not begin with a header record. This error typically occurs during the processing of IDocs or when importing data into SAP using batch input sessions.
  Cause:
  
  Missing Header Record: The first record in the session is expected to be a header record, but it is either missing or incorrectly formatted.
  Incorrect File Format: The file being processed may not be in the expected format, leading to the system not recognizing the first record as a header.
  Data Corruption: The data file may be corrupted or improperly structured, causing the system to misinterpret the records.
  Session Configuration: The session may not be configured correctly to handle the incoming data.
  
  Solution:
  
  Check the Input File: Ensure that the input file being processed has the correct structure. The first line should be a valid header record as per the specifications of the data being imported.
  Validate Data Format: Make sure that the data format matches the expected format for the transaction you are trying to process. This includes checking delimiters, data types, and field lengths.
  Review Session Logs: Look at the session logs for more detailed error messages that can provide insight into what went wrong.
  Recreate the Session: If the session is corrupted, you may need to recreate it. Ensure that the data is correctly formatted before doing so.
  Use Transaction Codes: If you are using transaction codes like SM35 to process batch input sessions, ensure that the session is created correctly and that the data is valid.
  Consult Documentation: Refer to SAP documentation or help resources for the specific transaction or IDoc type you are working with to ensure compliance with the required structure.
  
  Related Information:
  
  Transaction Codes: Familiarize yourself with relevant transaction codes such as SM35 (for processing batch input sessions) and WE02 (for monitoring IDocs).
  SAP Notes: Check SAP Notes for any known issues or patches related to the error message MG101.
  Data Mapping: Ensure that the data mapping between the source file and the SAP fields is correctly defined.
  Testing: If possible, test with a smaller dataset to isolate the issue and confirm that the header record is being processed correctly.
  
  By following these steps, you should be able to identify and resolve the issue causing the MG101 error in SAP.