Import Toolkit - Path cannot be empty error

I keep getting the following error when trying to use the Import Toolkit.@An error occurred on import: Path cannot be empty Parameter name: path@I have the following settings set.Data type to import: PagesImport options: Import new and overwrite existing pagesData source: SQL queryImport the pages under following parent path or parent node ID: /SitesWhere condition: {%SiteExternalMasterSiteID%} = SiteExternalMasterSiteIDI have the Kentico field @SiteExternalMasterSiteID@ mapped to the external datasource field @MasterSiteID@. I have tried every combo of MasterSiteID and SiteExternalMasterSiteID in the where clause to figure out why this is not working, but I get this same error every time.What am I doing wrong here?