How To Fix M2456 - Conversion from source unit & to unit & not allowed

SAP Error Message - Details

• Message type: E = Error

• Message class: M2 - LIS: Generating and updating info structures

• Message number: 456

• Message text: Conversion from source unit & to unit & not allowed

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message M2456 - Conversion from source unit & to unit & not allowed ?

  The SAP error message M2456, which states "Conversion from source unit & to unit & not allowed," typically occurs in the context of unit of measure (UoM) conversions in materials management or inventory management processes. This error indicates that the system is unable to convert a quantity from one unit of measure to another due to a lack of defined conversion factors or incompatible units.
  Causes:
  
  Missing Conversion Factors: The most common cause is that the conversion factors between the source unit and the target unit have not been defined in the system.
  Incompatible Units: The units may not be compatible for conversion. For example, trying to convert between weight and volume without a defined relationship.
  Incorrect Unit of Measure: The unit of measure used may not be valid or recognized in the context of the material or transaction.
  Configuration Issues: There may be issues in the configuration of the material master or the unit of measure settings in the SAP system.
  
  Solutions:
  
  
  Define Conversion Factors:
  
  Go to the material master record (transaction code MM02) and check the unit of measure settings.
  Ensure that the conversion factors between the source and target units are defined correctly in the "Units of Measure" tab.
  
  
  
  Check Unit Compatibility:
  
  Verify that the units you are trying to convert between are compatible. For example, ensure that both units are either weight or volume, and that a conversion factor exists.
  
  
  
  Review Material Master Data:
  
  Check the material master data for the specific material involved in the transaction. Ensure that the units of measure are correctly set up and that the material is configured to allow conversions.
  
  
  
  Configuration Settings:
  
  If you have access to configuration settings, check the settings for units of measure in the SAP IMG (Implementation Guide). Ensure that the necessary configurations for unit conversions are in place.
  
  
  
  Consult Documentation:
  
  Review SAP documentation or help resources for additional guidance on unit of measure conversions and any specific requirements for your industry or business processes.
  
  
  
  Contact SAP Support:
  
  If the issue persists after checking the above points, consider reaching out to SAP support for further assistance, especially if it appears to be a system or configuration issue.
  
  
  
  Related Information:
  
  Transaction Codes: MM02 (Change Material), MM03 (Display Material), and OME1 (Define Units of Measure).
  Unit of Measure Configuration: This can be found in the SAP IMG under Logistics > Material Management > Basic Settings > Units of Measure.
  Material Master Data: Understanding how to manage and configure material master data is crucial for resolving issues related to units of measure.
  
  By following these steps, you should be able to identify and resolve the cause of the M2456 error in SAP.