domain to xml mapping error

We're facing a Domain to XML Mapping error. For a given tumor prof. request (as XML format input string parameter), the soap webservice (using a microflow) is expected to return all related studies to that tumor from the source domain entities. The related attributes (parent tables to child tables) in the target XML file is being sourced from multiple entities in the source domain model. We have published web service. The top level of the XML Schema is an entity with no attributes in it, connected to the main table and elements which in turn is connected to other child tables. We created non-persistent response entities and matched all required entities in the mapping and left the optional ones empty, but while compiling we are getting the error "No association or microflow selected for obtaining objects" on the main table which is connected to the top level entity (which is also shown Optional in the domain to xml mapping). We tried creating another matching non-persistent entity at the top level to match the schema but didn't work (looks like Mendix automatically creates another entity above the top entity) Any guidance to fix this is appreciated. link text
1 answers

The entities in your domain model should mirror the webservice. In your case you need a CTCPublishServiceResponse entity. The clinicalTrialResult must have an association to that entity. This entity has no attibutes an serves as a placeholder.

The other way is to tick that level (Select elements) and see it can be missed.