Web-part error: (401) Unauthorized - sharepoint

Question

I have a little program that queries a web service, transforms the results using XSLT and displays them in a jQuery control. When I move the code into a web part it and deploy it, however I'm getting the following error:
The remote server returned an error: (401) Unauthorized.
This is the code that's loading my XSLT file, which is where I suspect the problem is:
XPathDocument xPathDoc;
XsltArgumentList args;
protected override void OnPreRender(EventArgs e)
{
xPathDoc = QueryRunner.GetQueryResults();
args = QueryRunner.GetColumnsToShow();
}
public static XPathDocument GetQueryResults()
{
OpacAccess.OpacAccess proxy = new OpacAccess.OpacAccess();
string result = string.Empty;
try
{
result = proxy.query("CompanyName", "username", "password",
ReadingList=\"London\"", 1000);
}
catch (Exception ex)
{
}
// Store the xml of the result
XPathDocument xPathDoc = new XPathDocument(new StringReader(result));
return xPathDoc;
}
protected override void RenderContents(HtmlTextWriter output)
{
XslTransform xslt = new XslTransform();
// Load the xslt file and perform the transformation
xslt.Load("http://rginfonet/Style%20Library/XSL%20Style%20Sheets/Liberty.xslt");
xslt.Transform(xPathDoc, args, output, null);
output.Flush();
}
Here's my stack trace if it's at all helpful to anyone:
[WebException: The remote server returned an error: (401) Unauthorized.] System.Net.HttpWebRequest.GetResponse() +5375213 System.Xml.XmlDownloadManager.GetNonFileStream(Uri uri, ICredentials credentials) +69 System.Xml.XmlDownloadManager.GetStream(Uri uri, ICredentials credentials) +3929371 System.Xml.XmlUrlResolver.GetEntity(Uri absoluteUri, String role, Type ofObjectToReturn) +54 System.Xml.XmlTextReaderImpl.OpenUrlDelegate(Object xmlResolver) +74 System.Threading.CompressedStack.runTryCode(Object userData) +70 System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup(TryCode code, CleanupCode backoutCode, Object userData) +0 System.Threading.CompressedStack.Run(CompressedStack compressedStack, ContextCallback callback, Object state) +108 System.Xml.XmlTextReaderImpl.OpenUrl() +186 System.Xml.XmlTextReaderImpl.Read() +208 System.Xml.XPath.XPathDocument.LoadFromReader(XmlReader reader, XmlSpace space) +217 System.Xml.XPath.XPathDocument..ctor(XmlReader reader, XmlSpace space) +20 System.Xml.Xsl.XsltOld.Compiler.LoadDocument(XmlTextReaderImpl reader) +85 System.Xml.Xsl.XslTransform.Load(String url, XmlResolver resolver) +100 System.Xml.Xsl.XslTransform.Load(String url) +25 LibertyControl.ResultsGrid.RenderContents(HtmlTextWriter output) +74 System.Web.UI.WebControls.WebControl.Render(HtmlTextWriter writer) +32 System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +27 System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +99 System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +25 System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +134 System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) +19 System.Web.UI.WebControls.WebControl.RenderContents(HtmlTextWriter writer) +10 System.Web.UI.WebControls.WebControl.Render(HtmlTextWriter writer) +32 System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +27 System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +99 System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +25 Microsoft.SharePoint.WebPartPages.SPChrome.RenderPartContents(HtmlTextWriter output, WebPart part) +66
[WebPartException: The remote server returned an error: (401) Unauthorized.] Microsoft.SharePoint.WebPartPages.SPChrome.RenderPartContents(HtmlTextWriter output, WebPart part) +140 Microsoft.SharePoint.WebPartPages.SPChrome.RenderWebPart(HtmlTextWriter output, WebPart part) +63 Microsoft.SharePoint.WebPartPages.WebPartZone.RenderZoneCell(HtmlTextWriter output, Boolean bMoreParts, WebPart part) +144 Microsoft.SharePoint.WebPartPages.WebPartZone.RenderWebParts(HtmlTextWriter output, ArrayList webParts) +495 Microsoft.SharePoint.WebPartPages.WebPartZone.Render(HtmlTextWriter output) +902 System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +27 System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +99 System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +25 System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +134 System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) +19 System.Web.UI.Control.Render(HtmlTextWriter writer) +10 System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +27 System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +99 System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +25 System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +134 System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) +19 System.Web.UI.HtmlControls.HtmlContainerControl.Render(HtmlTextWriter writer) +32 System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +27 System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +99 System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +25 System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +134 System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) +19 System.Web.UI.HtmlControls.HtmlForm.RenderChildren(HtmlTextWriter writer) +163 System.Web.UI.HtmlControls.HtmlContainerControl.Render(HtmlTextWriter writer) +32 System.Web.UI.HtmlControls.HtmlForm.Render(HtmlTextWriter output) +51 System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +27 System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +99 System.Web.UI.HtmlControls.HtmlForm.RenderControl(HtmlTextWriter writer) +40 System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +134 System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) +19 System.Web.UI.HtmlControls.HtmlContainerControl.Render(HtmlTextWriter writer) +32 System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +27 System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +99 System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +25 System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +134 System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) +19 System.Web.UI.Control.Render(HtmlTextWriter writer) +10 System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +27 System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +99 System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +25 System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +134 System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) +19 System.Web.UI.Page.Render(HtmlTextWriter writer) +29 System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +27 System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +99 System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +25 System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1266
Please let me know if you can lend some insight to what's causing this. Thanks!

Answer 1

The account responsible for rendering the webpart does not have access to the document library where you have the xslt located.
There are a few ways to get around this,
Give permissions to the system account to access that library
Use impersonation
If the xslt won't change that much then include it as a resource of the webpart

Answer 2

If you deployed your webpart in the bin folder ,might be that folder won't have permissions and not able to show you the webpart.Add sufficient permissions.