I have a transform that works on a large number of files. Every once and a 
while I get the following exception thrown:

A first chance exception of type 'System.Xml.Xsl.XslTransformException' 
occurred in System.Data.SqlXml.dll
System.Xml.Xsl.XslTransformException: Cannot convert a node-set which 
contains zero nodes or more than one node to a single node.
   at System.Xml.Xsl.Runtime.XsltConvert.ToNode(IList`1 listItems)
   at <xsl:template match="/">(XmlQueryRuntime 
{urn:schemas-microsoft-com:xslt-debug}runtime, XPathNavigator 
{urn:schemas-microsoft-com:xslt-debug}current)
   at Root(XmlQueryRuntime {urn:schemas-microsoft-com:xslt-debug}runtime)
   at Execute(XmlQueryRuntime {urn:schemas-microsoft-com:xslt-debug}runtime)
   at System.Xml.Xsl.XmlILCommand.Execute(Object defaultDocument, 
XmlResolver dataSources, XsltArgumentList argumentList, XmlSequenceWriter 
results)
   at System.Xml.Xsl.XmlILCommand.Execute(Object defaultDocument, 
XmlResolver dataSources, XsltArgumentList argumentList, XmlWriter writer, 
Boolean closeWriter)
   at System.Xml.Xsl.XmlILCommand.Execute(IXPathNavigable contextDocument, 
XmlResolver dataSources, XsltArgumentList argumentList, XmlWriter results)
   at System.Xml.Xsl.XmlILCommand.Execute(IXPathNavigable contextDocument, 
XmlResolver dataSources, XsltArgumentList argumentList, Stream results)
   at System.Xml.Xsl.XslCompiledTransform.Transform(IXPathNavigable input, 
XsltArgumentList arguments, Stream results)


Any hints on how I might be able to isolate the input that is causing the 
problem and maybe the line(s) in the stylesheet that are involved?

Thank you.

Kevin