System.Xml.Xsl.XslTransformException: An error occurred during a call to extension function 'GetSiteRootItem'. See InnerException for a complete description of the error. ---> System.ArgumentNullException: Value cannot be null.
Parameter name: item
   at Sitecore.Diagnostics.Assert.Throw(Exception e)
   at Sitecore.Configuration.Factory.CreateItemNavigator(Item item)
   at Beaconfire.SitecoreUtil.GetIteratorForItem(Item item)
   at Beaconfire.SitecoreUtil.GetSiteRootItem()
   at Beaconfire.XslExtension.GetSiteRootItem()
   --- End of inner exception stack trace ---
   at System.Xml.Xsl.Runtime.XmlExtensionFunction.Invoke(Object extObj, Object[] args)
   at System.Xml.Xsl.Runtime.XmlQueryContext.InvokeXsltLateBoundFunction(String name, String namespaceUri, IList`1[] args)
   at <xsl:template match="*" mode="main">(XmlQueryRuntime {urn:schemas-microsoft-com:xslt-debug}runtime, XPathNavigator {urn:schemas-microsoft-com:xslt-debug}current)
   at <xsl:template match="*">(XmlQueryRuntime {urn:schemas-microsoft-com:xslt-debug}runtime)
   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.XslCompiledTransform.Transform(IXPathNavigable input, XsltArgumentList arguments, XmlWriter results)
   at Mvp.Xml.Common.Xsl.MvpXslTransform.TransformToWriter(XmlInput defaultDocument, XsltArgumentList xsltArgs, XmlWriter xmlWriter)
   at Mvp.Xml.Common.Xsl.MvpXslTransform.Transform(XmlInput input, XsltArgumentList arguments, XmlOutput output)
   at Sitecore.Web.UI.WebControls.XslFile.DoRender(HtmlTextWriter output, Item item) Xsl file could not be processed: /xsl/content_splash_overlay.xslt

Error 500 - Internal Server Error

The action you requested has caused an internal server error. Please contact the website administrator to report this error.