Message type: E = Error
Message class:  CNV_10020 - Message class for package 10020 
Message number: 012
Message text: Subprogram &1 does not exist; check your input
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The SAP error message CNV_10020012 indicates that a specific subprogram (function module or method) referenced in your process does not exist or cannot be found. This error typically arises during data migration or conversion processes, particularly when using SAP's Conversion Tools.
Cause: Missing Subprogram: The subprogram (function module or method) specified in the error message is not available in the system. This could be due to: The subprogram has not been created or activated. The subprogram is part of a package that has not been imported or activated. The subprogram is incorrectly named or referenced. Incorrect Input: The input parameters or the context in which the subprogram is being called may be incorrect, leading to the system being unable to locate the subprogram. Transport Issues: If the subprogram was recently transported from another system, there may have been issues during the transport process that prevented it from being properly imported.
Solution: Check Subprogram Existence: Use transaction SE37 (Function Builder) or
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