Message type: E = Error
Message class:  CNV_OM_MWBGEN - SLO: Messages for Object Based MBW Generation 
Message number: 012
Message text: Preselection tables for root tables added (indirect selection)
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The SAP error message CNV_OM_MWBGEN012 typically relates to issues encountered during the data migration process, particularly when using the SAP S/4HANA Migration Cockpit or similar tools. This error indicates that preselection tables for root tables have been added, which may lead to indirect selection issues.
Cause: Data Model Changes: The error may arise due to changes in the data model where the root tables have been modified, and the preselection tables are not aligned with these changes.
Configuration Issues: There may be configuration issues in the migration settings or the mapping of the data. Missing or Incorrect Data: The preselection tables may not contain the necessary data or may have incorrect entries that prevent the migration process from proceeding. Incompatibility: The version of the migration tool or the source system may not be compatible with the target system.
Solution: Check Data Model: Review the data model to ensure that the root tables and preselection tables are correctly
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