Function use in a pre-2.0 stylesheet

xsl:function arrives in XSLT 2.0, so a function standing where the version in force is below 2.0 cannot run on the processor that version names. The version in force is the nearest version (or xsl:version) declared above it.

Either replace the function with an xsl:template that has a name, or raise the stylesheet to version="2.0".

Incorrect:

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
  <xsl:function name="my:foo">
    <!-- body logic -->
  </xsl:function>
</xsl:stylesheet>

Correct:

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
  <xsl:template name="foo">
    <!-- body logic -->
  </xsl:template>
</xsl:stylesheet>

or:

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="2.0">
  <xsl:function name="my:foo">
    <!-- body logic -->
  </xsl:function>
</xsl:stylesheet>