How To Fix FDT_CORE398 - Data type of Data Dictionary (DDIC) type '&1' does not match

SAP Error Message - Details

• Message type: E = Error

• Message class: FDT_CORE - Formula & Derivation Tool: Core

• Message number: 398

• Message text: Data type of Data Dictionary (DDIC) type '&1' does not match

What causes this issue?

The current BRFplus data object is bound to Data Dictionary (DDIC)
element &v1&. However, the system has determined that the type of the
data object and the DDIC element do not match. The deviation that has
been determined can relate to any of the following aspects:
Data object type (element, structure, table)
Elementary type of one or more fields in the data object (for example,
number, text, boolean, and so on).
This kind of problem is usually caused by changes done in the DDIC after
the binding relationship has been established.

System Response

The object cannot be activated.

How to fix this error?

Find out which version of data modeling is adequate for the use case you
are dealing with. Depending on your findings, proceed according to one
of the following alternatives:
BRFplus data object type suits better: Bind the data object to a DDIC
element that matches the current data object type. You can also decide
to remove the binding relationship and define the data object by means
of BRFplus.
DDIC element type suits better: Refresh the binding of the data object
so that it reflects the current DDIC type. Do not forget to check all
usages of the data object to make sure that no referencing object relies
on the data type that was in effect before.

Procedure for System Administrators

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

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message FDT_CORE398 - Data type of Data Dictionary (DDIC) type '&1' does not match ?

  The SAP error message FDT_CORE398 indicates that there is a mismatch between the data type defined in the Data Dictionary (DDIC) and the data type expected by the application or function module. This error typically arises in scenarios involving data mapping, especially when using the SAP Field Data Tool (FDT) or similar data handling mechanisms.
  Cause:
  
  
  Data Type Mismatch: The most common cause is that the data type defined in the DDIC for a particular field does not match the data type expected by the application. This can happen if:
  
  The field in the DDIC has been changed (e.g., from CHAR to NUMC) but the application code has not been updated accordingly.
  There is a discrepancy between the data types in different systems (e.g., development vs. production).
  The data type in the FDT configuration does not align with the DDIC definition.
  
  
  
  Incorrect Mapping: If you are using a mapping tool or configuration, the mapping might be incorrectly set up, leading to this error.
  
  
  Versioning Issues: If there are multiple versions of the same data structure or if the data structure has been modified without proper version control, it can lead to mismatches.
  
  
  Solution:
  
  
  Check Data Dictionary: Verify the data type of the field in the DDIC. You can do this by using transaction SE11 (Data Dictionary) to check the field's definition.
  
  
  Update Application Code: If the DDIC has been changed, ensure that the application code or any related configurations are updated to reflect these changes.
  
  
  Review Mapping Configuration: If you are using FDT or any mapping tool, review the mapping configuration to ensure that the data types are correctly aligned with the DDIC definitions.
  
  
  Consistency Check: Perform a consistency check between the development and production systems to ensure that the data types are the same across environments.
  
  
  Debugging: If the issue persists, consider debugging the application to trace where the mismatch is occurring. This can help identify the specific field or mapping that is causing the issue.
  
  
  Consult Documentation: Review any relevant documentation or release notes for changes that might have affected the data types.
  
  
  Related Information:
  
  Transaction Codes: SE11 (Data Dictionary), SE80 (Object Navigator), SE37 (Function Module), and SE24 (Class Builder) can be useful for checking definitions and debugging.
  SAP Notes: Check SAP Notes for any known issues or patches related to the FDT or specific data types.
  Field Data Tool (FDT): Familiarize yourself with the FDT documentation to understand how it handles data types and mappings.
  
  By following these steps, you should be able to identify and resolve the cause of the FDT_CORE398 error in your SAP environment.