Target XSD requires a value for this element

Hi

I'm looking at an issue we have with one of our PI scenarios.

We have a mapping that has an imported IDOC structure as both the source and target. For a number of fields we use the RFC lookup conversion function to call and RFC that translates values to those suitable for the target consumer system.

The issue we have is that the sending IDOC does not populate tags for empty fields so we won't always see all elements represented. The IDoc structure has occurrence set as 0..1 for these elements but yet the mapping still attempts to execute and so we get the error.

Cannot create target element /ns0:ZHR_XI_MAP_VALUES/VALUE_IN. Values missing in queue context. Target XSD requires a value for this element

This issue does not occur for field to field mappings. This also seems only to occur for the nodes being presented in the source xml. It will not complain about other nodes missing even though they too have RFC lookups mapped.

Any ideas?

Thanks,  Mark