Message type: E = Error
Message class:  CNV_MBT_09_A - Message class for drop-solution 
Message number: 029
Message text: RFC Error: &1 &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.
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_09_A029 RFC Error: &1 &2 typically indicates an issue related to Remote Function Call (RFC) communication between systems in the context of a data migration or conversion process. This error is often encountered during the execution of the SAP S/4HANA Migration Cockpit or other data migration tools.
Cause: Network Issues: There may be network connectivity problems between the source and target systems. RFC Destination Configuration: The RFC destination may not be correctly configured or may be missing. Authorization Issues: The user credentials used for the RFC connection may not have the necessary authorizations. System Availability: The target system may be down or not reachable. Incorrect Parameters: The parameters passed in the RFC call may be incorrect or not matching the expected format.
Solution: Check Network Connectivity: Ensure that there is proper network connectivity between the systems involved. You can use tools like ping or telnet to test connectivity. Verify RFC Destination: Go to transaction SM59 in
 Get instant SAP help. Sign up for our Free Essentials Plan.
Get instant SAP help. Sign up for our Free Essentials Plan. 
CNV_MBT_09_A028 No client was selected for deletion. Changes were saved into database.
 You have not selected any client for deletion. This will not result in data pertaining to any client being deleted during transfer to the receiver sy...
CNV_MBT_09_A027 Error while setting the Sort Criteria.
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_09_A030 Documentation not available.
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_09_A031 Error creating field catalog.
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.