dotnet/wpf · error · ApplicationException

SR.DocumentReferenceNotFound

Error message

SR.DocumentReferenceNotFound

What it means

DocumentReference._LoadDocument downloads the document at its Source URI and throws ApplicationException with SR.DocumentReferenceNotFound when the web response stream comes back null. This means WpfWebRequestHelper could not obtain a stream for the URI, i.e. the resource was not found or the request failed. It guards FixedDocumentSequence/XPS loading against silent null documents.

Solutions

1. Verify the DocumentReference.Source URI resolves to an existing document (fix the pack/file/http URI)
2. Use an absolute, correctly-formed pack URI (e.g. pack://application:,,,/Documents/FixedDocumentSequence.fdseq) instead of a broken relative path
3. Ensure the document file is included in project output (CopyToOutputDirectory) so it exists at runtime
4. Check the hosting web server/IIS actually serves the resource (test the URL in a browser) and the app has network access

Example fix

// before
docReference.Source = new Uri("Doc/fixdoc.xps", UriKind.Relative);
// after
docReference.Source = new Uri("pack://application:,,,/Doc/fixdoc.xps", UriKind.Absolute);

bool docExists = uri != null && (uri.IsFile ? File.Exists(uri.LocalPath) : true); if (!docExists) throw new FileNotFoundException(uri?.ToString());

try { var doc = docRef.GetDocument(); } catch (ApplicationException ex) { log.Error($"Document at {docRef.Source} not found", ex); ShowFallbackDocument(); }

When it happens

Trigger: Calling DocumentReference.GetDocument (or idpReloaded reload flow) when the Source URI points to a missing file, a wrong path, an unreachable server, or a handler that returns an empty/failed response so CreateRequestAndGetResponseStream returns null.

Common situations: Typo in the XPS/document path or pack URI; document served from a web server that returns 404; relative BaseUri resolved incorrectly after moving the app; file removed or renamed after build; running with restricted network/permissions in partial trust.

Understand the failure class

Background: 'Could not be found', 'does not exist', 'not found in database': the resource-not-found family when an ID, slug, key, or URI lookup comes back empty — this error's family across 20 libraries.

Related errors

• " }} " element found. Expected fixed page element ( }} ).
• ' ' ContentType is not valid.
• ' ' ContentType is not valid.
• Buffer address passed to GetText cannot be NULL.
• Cannot convert from type.

AI-assisted analysis of dotnet/wpf@81131a70a4 (2026-09-14). Data as JSON: /api/errors/b347c04e68cc9010. Report an issue: GitHub.

Appendix: source

Thrown at src/Microsoft.DotNet.Wpf/src/PresentationFramework/System/Windows/Documents/DocumentReference.cs:275

        // sync load a document
        private FixedDocument _LoadDocument()
        {
            FixedDocument idp = null;
            Uri uriToLoad = _ResolveUri();
            if (uriToLoad != null)
            {
                // Package-boundary guard. Reject any URI that escapes the XPS package.
                XpsLoadingContext.EnforcePackageRelativeUri(((IUriContext)this).BaseUri, uriToLoad);

                ContentType mimeType = null;
                Stream docStream = null;

                docStream = WpfWebRequestHelper.CreateRequestAndGetResponseStream(uriToLoad, out mimeType);
                if (docStream == null)
                {
                    throw new ApplicationException(SR.DocumentReferenceNotFound);
                }

                ParserContext pc = new ParserContext
                {
                    BaseUri = uriToLoad
                };

                if (BindUriHelper.IsXamlMimeType(mimeType))
                {
                    XpsValidatingLoader loader = new XpsValidatingLoader();
                    idp = loader.Load(docStream, ((IUriContext)this).BaseUri, pc, mimeType) as FixedDocument;
                }
                else if (MS.Internal.MimeTypeMapper.BamlMime.AreTypeAndSubTypeEqual(mimeType))
                {
                    idp = XamlReader.LoadBaml(docStream, pc, null, true) as FixedDocument;
                }
                else
                {

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