Message type: E = Error
Message class:  CNV_20700 - Material number conversion 
Message number: 066
Message text: In Index MDTC AR read: &1 and changed: &2
Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of messages in the SAP system have a message text, however this is frequently insufficient to comprehend or resolve the problem.
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The SAP error message CNV_20700066 typically occurs during data migration processes, particularly when using the SAP S/4HANA Migration Cockpit or other data migration tools. This error indicates that there is a discrepancy between the data being read from the source system and the data that has been changed or updated in the target system.
Cause: The error message CNV_20700066 can be caused by several factors, including: Data Consistency Issues: The data in the source system may not match the expected format or structure in the target system. Concurrency Issues: If multiple processes are trying to read or write to the same data simultaneously, it can lead to inconsistencies. Data Locking: The data being accessed may be locked by another process, preventing the migration tool from reading or updating it.
Configuration Issues: Incorrect configuration settings in the migration tool or the target system can lead to this error.
Solution: To resolve the CNV_20700066 error, you can take the following
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