System.Xml.Xsl.XslTransformException: An error occurred during a call to extension function 'CollectRSSArticles'. See InnerException for a complete description of the error. ---> System.Net.WebException: The request was aborted: Could not create SSL/TLS secure channel.
at System.Net.HttpWebRequest.GetResponse()
at System.Xml.XmlDownloadManager.GetNonFileStream(Uri uri, ICredentials credentials, IWebProxy proxy, RequestCachePolicy cachePolicy)
at System.Xml.XmlUrlResolver.GetEntity(Uri absoluteUri, String role, Type ofObjectToReturn)
at System.Xml.XmlTextReaderImpl.FinishInitUriString()
at System.Xml.XmlReaderSettings.CreateReader(String inputUri, XmlParserContext inputContext)
at ELCAorg.SharepointDataPull.CollectRSSArticles(String url)
--- 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="*">(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 System.Xml.Xsl.XmlILCommand.Execute(Object defaultDocument, XmlResolver dataSources, XsltArgumentList argumentList, XmlWriter writer)
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/RSS/widgets/wp_rss.xslt