Message type: E = Error
Message class:  CNVMBTRFC - Messages used in RFC Management and its objects 
Message number: 012
Message text: No RFC Destination type 3 (Connection to R/3 System) found.
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The SAP error message CNVMBTRFC012 indicates that the system is unable to find a Remote Function Call (RFC) destination of type 3, which is typically used for connecting to an R/3 system. This error often arises during data migration or when using certain tools that require communication with an R/3 system.
Cause: Missing RFC Destination: The most common cause is that the required RFC destination has not been created in the SAP system. Incorrect Configuration: The RFC destination may exist but is incorrectly configured or inactive. Authorization Issues: The user may not have the necessary authorizations to access the RFC destination. Network Issues: There could be network connectivity issues preventing the system from reaching the R/3 system. System Configuration: The system may not be properly configured to recognize the R/3 system.
Solution: Create or Check RFC Destination: Go to transaction SM59 in the SAP GUI. Check if the RFC destination of type 3 (R/3 connection) exists. If it does not exist,
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