XML Data File Import options: Have an xquery, but am told it's empty or null

Save the attached sample XML file to a local directory (unzip it, please) Use the "Model Local XML File Source" action set Connect to the directory in which you saved the XML file Create the source model from the XML file source Specify the local file option On the wizard's second page, verify you have the correct file, select the project as the location, and give the model a name On the 3rd page, expand the first medline citation and, for each of the following, "Add selection as new column" PMID Date Created Year Date Created Month Date Created Day Article Article Title Affiliation During the time you added attributes as columns, the error status at the top of the dialog has read: XQuery expression cannot be null or empty. The Next button is disabled.