Message type: E = Error
Message class:  CNV_OM_PRESEL - Messages for LT Object Based Preselection 
Message number: 168
Message text: No authorization to start simulation
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_OM_PRESEL168 indicates that a user does not have the necessary authorization to start a simulation in the context of a specific operation or transaction. This error typically arises in scenarios involving data migration or conversion processes, particularly when using tools like the SAP S/4HANA Migration Cockpit or other conversion tools.
Cause: The primary cause of this error is a lack of appropriate authorizations assigned to the user role. The user attempting to start the simulation does not have the required permissions to execute the operation.
Solution: To resolve this issue, you can follow these steps: Check User Authorizations: Use transaction code SU53 immediately after the error occurs to check the authorization check that failed. This will provide insights into which specific authorization object is missing. Review Role Assignments: Go to transaction PFCG to review the roles assigned to the user. Ensure that the user has the necessary roles that include the required authorizations for
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