XmlCompiledTransform.Load间歇性地引发NullReferenceException

Question

I have the following code snippet

this.xslCompiledTransform = new XslCompiledTransform();

// initialize xsl transform
using (Stream xsltStream = currentAssembly.GetManifestResourceStream(this.TransformationFile))
using (XmlReader schemaReader = XmlReader.Create(xsltStream))
{
    XsltSettings settings = new XsltSettings() { EnableScript = true };
    this.xslCompiledTransform.Load(schemaReader, settings, null);
}

It throws NullReferenceExcecption sometime and sometime it works on the same xslt file.

Could you please tell what is wrong with the above code? Any help will be appreciated.

Below is the stack trace

    Object reference not set to an instance of an object.

Stack Trace:
   at System.Xml.Xsl.IlGen.XmlILVisitor.VisitFor(QilIterator ndFor)
   at System.Xml.Xsl.IlGen.XmlILVisitor.Visit(QilNode nd)
   at System.Xml.Xsl.IlGen.XmlILVisitor.NestedVisit(QilNode nd, Type itemStorageType, Boolean isCached)
   at System.Xml.Xsl.IlGen.XmlILVisitor.NestedVisitEnsureStack(QilNode nd, Type itemStorageType, Boolean isCached)
   at System.Xml.Xsl.IlGen.XmlILVisitor.VisitXPathNodeValue(QilUnary ndVal)
   at System.Xml.Xsl.IlGen.XmlILVisitor.Visit(QilNode nd)
   at System.Xml.Xsl.IlGen.XmlILVisitor.NestedVisit(QilNode nd, Type itemStorageType, Boolean isCached)
   at System.Xml.Xsl.IlGen.XmlILVisitor.NestedVisitEnsureStack(QilNode nd, Type itemStorageType, Boolean isCached)
   at System.Xml.Xsl.IlGen.XmlILVisitor.VisitXsltInvokeEarlyBound(QilInvokeEarlyBound ndInvoke)
   at System.Xml.Xsl.IlGen.XmlILVisitor.Visit(QilNode nd)
   at System.Xml.Xsl.IlGen.XmlILVisitor.NestedVisit(QilNode nd, Type itemStorageType, Boolean isCached)
   at System.Xml.Xsl.IlGen.XmlILVisitor.VisitTextCtor(QilUnary ndText, Boolean disableOutputEscaping)
   at System.Xml.Xsl.IlGen.XmlILVisitor.Visit(QilNode nd)
   at System.Xml.Xsl.IlGen.XmlILVisitor.VisitLoop(QilLoop ndLoop)
   at System.Xml.Xsl.IlGen.XmlILVisitor.Visit(QilNode nd)
   at System.Xml.Xsl.IlGen.XmlILVisitor.NestedVisit(QilNode nd, Type itemStorageType, Boolean isCached)
   at System.Xml.Xsl.IlGen.XmlILVisitor.NestedVisit(QilNode nd)
   at System.Xml.Xsl.IlGen.XmlILVisitor.VisitElementCtor(QilBinary ndElem)
   at System.Xml.Xsl.IlGen.XmlILVisitor.Visit(QilNode nd)
   at System.Xml.Xsl.IlGen.XmlILVisitor.NestedVisit(QilNode nd, Type itemStorageType, Boolean isCached)
   at System.Xml.Xsl.IlGen.XmlILVisitor.NestedVisit(QilNode nd)
   at System.Xml.Xsl.IlGen.XmlILVisitor.VisitElementCtor(QilBinary ndElem)
   at System.Xml.Xsl.IlGen.XmlILVisitor.Visit(QilNode nd)
   at System.Xml.Xsl.IlGen.XmlILVisitor.NestedVisit(QilNode nd, Type itemStorageType, Boolean isCached)
   at System.Xml.Xsl.IlGen.XmlILVisitor.VisitSequence(QilList ndSeq)
   at System.Xml.Xsl.IlGen.XmlILVisitor.Visit(QilNode nd)
   at System.Xml.Xsl.IlGen.XmlILVisitor.NestedVisit(QilNode nd, Type itemStorageType, Boolean isCached)
   at System.Xml.Xsl.IlGen.XmlILVisitor.NestedVisit(QilNode nd)
   at System.Xml.Xsl.IlGen.XmlILVisitor.VisitElementCtor(QilBinary ndElem)
   at System.Xml.Xsl.IlGen.XmlILVisitor.Visit(QilNode nd)
   at System.Xml.Xsl.IlGen.XmlILVisitor.NestedVisit(QilNode nd, Type itemStorageType, Boolean isCached)
   at System.Xml.Xsl.IlGen.XmlILVisitor.NestedVisit(QilNode nd)
   at System.Xml.Xsl.IlGen.XmlILVisitor.VisitConditional(QilTernary ndCond)
   at System.Xml.Xsl.IlGen.XmlILVisitor.Visit(QilNode nd)
   at System.Xml.Xsl.IlGen.XmlILVisitor.NestedVisit(QilNode nd, Type itemStorageType, Boolean isCached)
   at System.Xml.Xsl.IlGen.XmlILVisitor.NestedVisit(QilNode nd)
   at System.Xml.Xsl.IlGen.XmlILVisitor.Function(QilFunction ndFunc)
   at System.Xml.Xsl.IlGen.XmlILVisitor.Visit(QilExpression qil, GenerateHelper helper, MethodInfo methRoot)
   at System.Xml.Xsl.XmlILGenerator.Generate(QilExpression query, TypeBuilder typeBldr)
   at System.Xml.Xsl.XslCompiledTransform.LoadInternal(Object stylesheet, XsltSettings settings, XmlResolver stylesheetResolver)

Answer 1

Directly copied from XslCompiledTransform.Load Method note section:

There are differences between XSLT compiled in Debug mode and XSLT compiled in Release mode. In some situations, style sheets compiled in Debug mode will not throw errors during Load, but will later fail during Transform. The same style sheet compiled in Release mode will fail during Load. An example of such behavior is when a variable that is not of a node-set type is assigned to an expression where a node-set is required.