I am creating a configured operation on the idoc adapter for the enterprise integrator 4.1.1 and I get the following error message:

Not Available (516-5163): The adapter process was unable to supply a set of valid values for the following reason: (301) IDoc/RFC exception:: CIDocDataSegment constructor(string): ZCUST does not form name or type of a segment

is this because of the assumption that custom created segments defined in SAP should start with Z1?

thanks for any help on the subject!