How To Fix MN160 - Reference size &1 not defined (function module &2)

SAP Error Message - Details

• Message type: E = Error

• Message class: MN - Message class for subsequent settlement (Purchasing)

• Message number: 160

• Message text: Reference size &1 not defined (function module &2)

What causes this issue?

An evaluation of condition records with reference magnitude &V1& is not
possible.
The program called for evaluation cannot process reference magnitude
&V1&.

System Response

The condition record is not evaluated.

How to fix this error?

Contact your system administrator, as a program error has occurred.
The error occurred in function module &V2&.
Either this was called with incorrect data, or evaluation of condition
records with reference magnitude &V1& is not programmed.
The condition record concerned has (internal) number &V3&, and
condition item number &V4&.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message MN160 - Reference size &1 not defined (function module &2) ?

  The SAP error message MN160, which states "Reference size &1 not defined (function module &2)," typically occurs in the context of material management or inventory management when there is an issue with the configuration of reference sizes in the system. This error can arise in various scenarios, such as during the creation or modification of materials, or when executing certain functions that rely on reference sizes.
  Cause:
  
  Missing Configuration: The reference size specified in the error message is not defined in the system. This could be due to missing entries in the relevant configuration tables.
  Incorrect Function Module: The function module mentioned in the error may not be correctly set up or may not be able to access the required reference size data.
  Data Inconsistency: There may be inconsistencies in the data related to materials or reference sizes, leading to the system being unable to find the necessary information.
  
  Solution:
  
  
  Check Reference Size Configuration:
  
  Go to the configuration settings for reference sizes in the SAP system. This is typically found in the IMG (Implementation Guide) under the relevant module (e.g., Materials Management).
  Ensure that the reference size specified in the error message is defined and correctly configured.
  
  
  
  Verify Material Master Data:
  
  Check the material master data for the material in question. Ensure that all necessary fields, including reference sizes, are filled out correctly.
  If the material is missing a reference size, you may need to add it.
  
  
  
  Review Function Module:
  
  Investigate the function module mentioned in the error message. Ensure that it is correctly implemented and that it has access to the necessary data.
  If you have access to ABAP development, you can check the code of the function module to see if there are any issues.
  
  
  
  Consult Documentation:
  
  Review SAP documentation or notes related to the error message MN160. There may be specific notes or patches available that address this issue.
  
  
  
  Contact SAP Support:
  
  If the issue persists after checking the configuration and data, consider reaching out to SAP support for further assistance. Provide them with the error message details and any relevant context.
  
  
  
  Related Information:
  
  Transaction Codes: You may use transaction codes like MM01 (Create Material), MM02 (Change Material), or MM03 (Display Material) to check and modify material master data.
  Tables: Relevant tables to check include MARA (General Material Data), MARC (Plant Data for Material), and MAST (Material to BOM Link).
  SAP Notes: Search for SAP Notes related to error MN160 in the SAP Support Portal for any known issues or fixes.
  
  By following these steps, you should be able to identify and resolve the cause of the MN160 error in your SAP system.