<xsl:when test="[@xsi:type='CTextEx' or  @xsi:type='CTextRingEx']">

XPath expressions never start with a [ wgich is a filter operation that
apples to the sequence on its left hand side. You just want
 <xsl:when test="@xsi:type='CTextEx' or  @xsi:type='CTextRingEx'">
if your whole template is an xsl:choose it os more idiomatic (and in
some cases more efficient) to write it as separte templates so:)
  <xsl:template match="Object[@xsi:type='CTextEx']">


  <xsl:template match="Object">
...

  <xsl:template match="Object[@xsi:type='CTextEx' or  @xsi:type='CTextRingEx']">

...


David

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