How To Fix DMC_EXCEPTION003 - Structure &1 cannot be a lookup table; it is mapped to target structures

DMC_EXCEPTION003 - Overview

• Message type: E = Error

• Message class: DMC_EXCEPTION - Message class for exception texts

• Message number: 003

• Message text: Structure &1 cannot be a lookup table; it is mapped to target structures

A lookup table contains records that are looked up from a field in
another table to fill in the value of that field. The table can be
referenced by rules and used by mapping operations, but does not
directly provide content for fields in the target system.

Error message extract from SAP system. Copyright SAP SE.

DMC_EXCEPTION003 - Details

• The SAP error message DMC_EXCEPTION003 indicates that there is an issue with the data mapping in the Data Migration Cockpit (DMC) where a structure is being treated as a lookup table, but it is already mapped to target structures. This typically occurs during data migration processes when the system expects a certain configuration for the data structures involved.
  
  Cause:
  
  Incorrect Mapping: The structure in question is likely being used in a way that conflicts with its intended use as a lookup table. Lookup tables are generally used to provide reference data, while target structures are meant to hold the actual data being migrated.
  
  Configuration Issues: There may be a misconfiguration in the data migration settings or the way the structures are defined in the DMC.
  Duplicate Usage: The same structure might be mapped to multiple target structures, which can lead to confusion in how the data should be processed.
  
  
  Solution:
  
  Review Mapping: Check the mapping configuration