some colleagues complains that although the necessary customizing for followup opportunity creation is done, still they could not create follow up opportunity based on an appointment.
An error message is displayed. In fact it already gives hint about the failure reason.
The target transaction type determination is done based on two levels:
level 1: done based on transaction type level. The FM below returns all supported follow up transaction type for "CX02".
The types for opportunity are also in result.
level 2: there is filtering logic on result of level 1, based on instance level.
It is designed that if one source document has errors, only "activities" is allowed as target transaction type.
once I fixed the error for current activity:
The opportunity follow up also works well: