Message type: E = Error
Message class:  CNV - Conversion: Messages for Conversion Services (CNCC) 
Message number: 406
Message text: IMG structure &1 or package &2 does not exist
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The SAP error message CNV406 indicates that a specific IMG (Implementation Guide) structure or package does not exist in the system. This error typically arises during data migration or system conversion processes, particularly when using SAP's tools for data transfer or system upgrades.
Cause: Missing IMG Structure/Package: The specified IMG structure or package is not defined in the system. This could be due to an incomplete installation or configuration. Incorrect Configuration: The system might be looking for a structure or package that is not relevant to the current system version or configuration. Transport Issues: If the IMG structure or package was supposed to be transported from another system, it may not have been successfully transported. Custom Development: If the structure or package is custom-developed, it may not have been properly created or activated.
Solution: Check Configuration: Verify that the IMG structure or package you are trying to access is indeed defined in the system. You can do
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