Some of the XML files have incorrect URLs in the schema location, e.g. https://github.com/hpde/NASA/blob/master/NumericalData/MMS/4/FIELDS/FGM/Survey/Level2/PT0.125S.xml has the URL: http://www.spase-group.org/data/schema/spase-2-5-0.xsd It should probably be: https://www.spase-group.org/data/schema/spase-2.5.0.xsd