How To Fix C1821 - Inconsistent characteristic value assignment

SAP Error Message - Details

• Message type: E = Error

• Message class: C1 - Characteristics maintenance messages

• Message number: 821

• Message text: Inconsistent characteristic value assignment

What causes this issue?

You want to change the value assigned to a characteristic. However, the
change causes inconsistency, so the new value is not allowed.
The inconsistency may be for the following reasons:
A precondition or selection condition is violated.
The characteristic is a single-value characteristic, and different
values have been set by constraints, actions, or procedures.
In classification, inconsistencies occur when you change the value set
of a characteristic if objects or classes have already been classified
with values from the previous value set (for example, in the case of a
configurable material or a generic material).

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?

Choose <PF>Inconsistencies</> to see what triggered the inconsistency.
You can also use the explanation facility for more information.
Delete the values that triggered the inconsistency.
You can only change or delete a value or value set that has already been
used to classify objects if you delete the existing allocations.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message C1821 - Inconsistent characteristic value assignment ?

  The SAP error message C1821, which states "Inconsistent characteristic value assignment," typically occurs in the context of SAP's classification system. This error indicates that there is a mismatch or inconsistency in the assignment of characteristic values to a classification object, such as a material or a document.
  Causes of Error C1821
  
  Inconsistent Data: The characteristic values assigned to a classification object do not match the expected values defined in the classification system.
  Missing Characteristics: Required characteristics may not be assigned to the object, leading to inconsistencies.
  Incorrect Value Assignment: The values assigned to characteristics may not be valid or may not conform to the defined value range for those characteristics.
  Changes in Class Structure: If the class structure has been modified (e.g., characteristics added or removed), existing assignments may become inconsistent.
  Data Migration Issues: If data has been migrated from another system, inconsistencies may arise due to differences in classification setups.
  
  Solutions to Error C1821
  
  Check Characteristic Assignments: Review the characteristic assignments for the object in question. Ensure that all required characteristics are assigned and that their values are valid.
  Validate Characteristic Values: Ensure that the values assigned to characteristics are within the allowed range and conform to the definitions in the classification system.
  Review Class Structure: If there have been recent changes to the class structure, verify that the changes have been correctly implemented and that all objects are updated accordingly.
  Use Transaction CL02: You can use transaction CL02 (Change Class) to check and modify the class and its characteristics. Ensure that the characteristics are correctly defined and assigned.
  Data Consistency Check: Run consistency checks on the classification data to identify and rectify any inconsistencies. This can often be done through specific SAP reports or tools designed for data validation.
  Consult Documentation: Refer to SAP documentation or help resources for specific guidance on handling classification errors.
  
  Related Information
  
  Transaction Codes: Familiarize yourself with relevant transaction codes such as CL01 (Create Class), CL02 (Change Class), and CL03 (Display Class) for managing classification data.
  SAP Notes: Check SAP Notes for any known issues or patches related to classification errors. SAP Notes can provide specific solutions or workarounds for known problems.
  Support: If the issue persists, consider reaching out to SAP support or your internal SAP support team for further assistance.
  
  By following these steps, you should be able to identify and resolve the cause of the C1821 error in your SAP system.