Message type: E = Error
Message class:  CNV10300 - Message class for development class CNV_10300 
Message number: 021
Message text: KVEWE='E'was used for KAPPL=&1,KOTABNR=&2, though more selection!
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The SAP error message CNV10300021 typically relates to issues encountered during data migration or conversion processes, particularly when using the SAP S/4HANA Migration Cockpit or similar tools. The message indicates that a specific value for the field KVEWE (which is likely a key or identifier in the context of the migration) was used, but there were additional selection criteria that were not met or considered.
Cause: Data Inconsistency: The error may arise due to inconsistencies in the data being migrated. For example, if the data in the source system does not match the expected format or values in the target system. Selection Criteria: The error suggests that there are more selection criteria that should have been applied, but they were not. This could be due to misconfiguration in the migration settings or parameters.
Configuration Issues: There may be issues with the configuration of the migration object or the mapping of fields between the source
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