You must specify RFC destinations for the systems with the source and target component releases of the planned synchronization objects. This allows you to specify synchronization objects in the specification tool and perform checks.
You have created RFC destinations for your components with the transaction SM59. You are in the specification tool initial screen.
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Choose Goto → Change RFC Destinations.
You go to the Change Supported Components, Releases and RFC Destinations dialog screen.
Choose the New Entries pushbutton or the Edit → New Entries menu.
Enter the required data.
The system checks which software components are in the local system, and gives them the RFC destination NONE. You can use these components.
Save your entries.