The Import functionality, built in Mendix based on an XSD, requires that all the element 'ImportRefNr' are filled with a value. If that isn't the case Mendix will give you this error and cancel the import.
In your XML an element 'ImportRefNr' (The path to the element is:TableMappingList|TableMappings|ImportCall_TableMapping|ImportCall|ImportRefNr attribute: DatabaseReplication.ImportCall.ImportRefNr) isn't filled with a value. You should search in the XML for the subelement and maybe remove the parent element 'ImportCall'.
In the DomToXML_TableMapping_v3 double click on importcalling and export the value of refnr also to importrefnr.
Were you able to find a solution?
I'm facing same issue:
While trying to export TM from Database Replication of Table Mapping where there is Reference to other entity used I'm getting this error.