How To Fix CO851 - Error while converting order unit of measure &1

SAP Error Message - Details

• Message type: E = Error

• Message class: CO - PPC order processing messages

• Message number: 851

• Message text: Error while converting order unit of measure &1

What causes this issue?

An error occurred when the order quantity was being converted from &V1&
to the header unit &V2&.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Check the settings in measurement unit maintenance.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message CO851 - Error while converting order unit of measure &1 ?

  The SAP error message CO851, which states "Error while converting order unit of measure &1," typically occurs in the context of production orders or other related processes where unit of measure (UoM) conversions are involved. This error indicates that there is an issue with converting the order's unit of measure to the required unit of measure for processing.
  Causes of CO851 Error
  
  
  Incorrect Unit of Measure Configuration: The unit of measure for the material or order may not be correctly defined in the system. This can include missing conversion factors or incorrect settings in the material master.
  
  
  Missing Conversion Factors: If the conversion factors between the base unit of measure and the order unit of measure are not defined, the system will not be able to perform the conversion.
  
  
  Inconsistent Data: There may be inconsistencies in the data related to the material, such as the unit of measure settings in the material master or the order itself.
  
  
  Invalid UoM: The unit of measure specified in the order may not be valid for the material being processed.
  
  
  Custom Code or Enhancements: If there are custom developments or enhancements in the system that affect unit of measure conversions, they may be causing the error.
  
  
  Solutions to CO851 Error
  
  
  Check Material Master Data:
  
  Go to the material master (transaction code MM03) and check the unit of measure settings.
  Ensure that the base unit of measure and any alternative units of measure are correctly defined and that conversion factors are specified.
  
  
  
  Review Order Data:
  
  Check the production order or relevant document to ensure that the unit of measure is valid and correctly specified.
  
  
  
  Define Conversion Factors:
  
  If conversion factors are missing, you can define them in the material master under the "Units of Measure" view.
  
  
  
  Validate UoM Settings:
  
  Ensure that the unit of measure used in the order is valid for the material. You can check this in the material master or by using transaction code CUNI (Unit of Measure Conversion).
  
  
  
  Check for Custom Code:
  
  If there are any custom developments or enhancements that might affect unit of measure conversions, review them to ensure they are functioning correctly.
  
  
  
  Consult SAP Notes:
  
  Check the SAP Support Portal for any relevant SAP Notes that might address this specific error or provide additional guidance.
  
  
  
  Related Information
  
  
  Transaction Codes:
  
  MM03: Display Material Master
  CUNI: Maintain Units of Measure
  CO02: Change Production Order
  CO03: Display Production Order
  
  
  
  Documentation: Refer to SAP Help documentation for detailed information on unit of measure handling and production order processing.
  
  
  SAP Community: Engage with the SAP Community forums for insights from other users who may have encountered and resolved similar issues.
  
  
  By following these steps, you should be able to identify the root cause of the CO851 error and implement the necessary corrections to resolve it.