Message type: E = Error
Message class:  CNV_MBT_DEX - DMIS Data Extract related messages 
Message number: 124
Message text: New logic control file cannot be imported with old control file logic
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.
To make things easier, more detailed information is frequently added to describe the issue, how to fix it, and the necessary steps or configuration modifications.
Unfortunately, there isn't any extra information in this error notice.
First, use our AnswerBot below to get a possible cause and solution (requires a premium subscription).
Also, review the in-depth Common Questions & Answers listed below; you could discover a solution there or be able to connect with others who have faced similar challenges.
You can also try searching the SAP support portal (support.sap.com) but you need a special user ID to access it. It is possible that an SAP support note exists that provides additional details about the mistake or even steps for fixing it.
The SAP error message CNV_MBT_DEX124 indicates that there is a mismatch between the logic of the control files being used in a data migration or conversion process. Specifically, it suggests that a new logic control file is being attempted to be imported while an old control file logic is still in use. This can occur during data migration projects, especially when using the SAP S/4HANA Migration Cockpit or similar tools.
Cause: Version Mismatch: The control files (which define how data is transformed and loaded) have been updated or changed, but the system is still referencing an older version of the control file logic. Inconsistent Configuration: The configuration settings or parameters in the migration cockpit may not be aligned with the new control file logic. Incomplete Migration Steps: Previous migration steps may not have been completed successfully, leading to inconsistencies in the control file logic.
Solution: Check Control File Versions: Ensure that you are using the correct
 Get instant SAP help. Sign up for our Free Essentials Plan.
Get instant SAP help. Sign up for our Free Essentials Plan. 
CNV_MBT_DEX123 Data trying to get imported with GENERIC_READ_WRITE = &
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
CNV_MBT_DEX122 Data exported with GENERIC_READ_WRITE = &
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
CNV_MBT_DEX200 * general messages
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
CNV_MBT_DEX201 Invalid Call of function module &
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
Click on this link to search all SAP messages.