Deb -- Nothing jumps to my mind right away. But a bit more information might be helpful. * What version of oXygen? * When do you get the message? (When transforming? If so, with what scenario, i.e. which stylesheet and settings?) * Do you have TEI P5 enabled in the Document Type Association part of the Options dialog? (I'm not sure it matters ... I think the explicit <?RNGSchema?> PI will override the association, but I'm not sure.) (BTW, unless you're using SVG and MathML, you may as well delete their namespace associations.) > I'm using oXygen and lately have been getting this message: > E [oNVDL] org.xml.sax.SAXParseException-no implementation available > for schema language with namespace URI > "http://www.tei-c.org/ns/1.0" > Here's the beginning of my teiHeader, from the oXygen template for > TEI P5-All: > <?oxygen RNGSchema="http://www.tei-c.org/release/xml/tei/custom/schema/relaxng/tei_all.rng" type="xml"?> > <TEI > xmlns:xi="http://www.w3.org/2001/XInclude" > xmlns:svg="http://www.w3.org/2000/svg" > xmlns:math="http://www.w3.org/1998/Math/MathML" > xmlns="http://www.tei-c.org/ns/1.0"> > <teiHeader type="text"> > Any clues as to why? My documents transform into html via oXygen just fine.