Target xsi:type must be set before descendent elements or attributes are stored

When the XML is selected for the target message, the xsi:type attribute must be set before referring to the sub-element with a type modifier. For example:

=realtype --> root.child.&xsi:type
=myvalue --> root.child{realtype}.&realattr

In this example, if the type has not been set, then it is incorrect:

=myvalue --> root.child{realtype}.&realattr 

Because the child’s defined type does not have the realattr attribute, it produces this error:

XML Path Resolution Error: The specified element child of type abstracttype does not match path type modifier realtype.