XSL error with correct XML / XSL

Hello, I am trying to process a XML document with an XSL style sheet. Both are produced automatically. When i call xslt_process I get the following error : Warning : Sablotron error on line 15 : XML parser error 7: mismatched tag in <the path to my PHP class> on line 183 I checked both XML and XSL with a call to xml_parse and both are correct. I also tried to apply my XSL to the XML with cooktop and it worked perfectly. So is anyone here that have an idea ? Does a mean to have more precise error message than the one above ? My XML is : <?xml version='1.0'?> <acte><champ id="DISPOSITIF">mon dispositif</champ> <champ id="VISAS">mes visas </champ> <champ id="CONSIDERANTS">mes considerants </champ> <champ id="OBJET">mon acte de test</champ> <champ id="RESUME">mon résumé</champ> <champ id="LIEN_EXTERNE"></champ> <signataires> <signataire> <fonction>développeur</fonction> <prenom>Olivier</prenom> <nom>DUHART</nom> </signataire> </signataires> </acte> my XSL is : <?xml version="1.0" ?> <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"> <xsl:template match="acte"><html><head></head><body leftmargin="0" topmargin="0" marginheight="0" marginwidth="0"><P> <U><STRONG>DISPOSITIF :</STRONG></U> <xsl:value-of select="champ[@id='DISPOSITIF']/text()"/></P> <P><STRONG><U>VISAS </U></STRONG><xsl:value-of select="champ[@id='VISAS']/text()"/></P> <P><STRONG><U>CONSIDERANTS : </U></STRONG><xsl:value-of select="champ[@id='CONSIDERANTS']/text()"/></P> <P> </P> <P><table><tr><td><xsl:apply-templates select="//signataire"/></td></tr></table></P></body></html></xsl:template> <xsl:template match="delegant">P/ le <xsl:value-of select="fonction"/><br/><xsl:value-of select="prenom"/> <xsl:value-of select="nom"/><br/></xsl:template><xsl:template match="signataire"><td><xsl:apply-templates select="delegant"/>le <xsl:value-of select="fonction"/><br/><xsl:value-of select="prenom"/> <xsl:value-of select="nom"/><br/></td></xsl:template></xsl:stylesheet> Thanks Olivier