dotnet/wpf · error · ArgumentException

SR.HyperLinkTargetNotFound

Error message

SR.HyperLinkTargetNotFound

What it means

NavigationService.OnRequestNavigate() handles a Hyperlink click; when the hyperlink's target (NavigateUri) cannot be resolved — the handler does not produce a navigation target — it throws ArgumentException with HyperLinkTargetNotFound. It signals that the URI the hyperlink points at has no resolvable destination at that point.

Solutions

  1. Use an absolute pack URI, e.g. pack://application:,,,/MyPage.xaml, instead of an ambiguous relative URI
  2. Ensure the hyperlink is hosted in a Frame or NavigationWindow that can resolve the target
  3. Verify the NavigateUri and TargetName spellings and that the target resource exists in the assembly
  4. Handle NavigationService.NavigationFailed to catch resolution problems gracefully

Example fix

<!-- before -->
<TextBlock><Hyperlink NavigateUri="Page2.xaml">Go</Hyperlink></TextBlock>
<!-- after -->
<TextBlock><Hyperlink NavigateUri="pack://application:,,,/MyApp;component/Page2.xaml">Go</Hyperlink></TextBlock>
Defensive patterns

Strategy: validation

Validate before calling

bool resolvable = hyperlink.NavigateUri != null && hyperlink.NavigateUri.IsAbsoluteUri;
if (!resolvable) hyperlink.NavigateUri = new Uri("pack://application:,,,/TargetPage.xaml", UriKind.Absolute);

Type guard

bool HasResolvableTarget(Hyperlink h) =>
    h?.NavigateUri != null && h.NavigateUri.ToString().StartsWith("pack://");

Try / catch

try { frame.NavigationService.Navigate(hyperlink.NavigateUri); }
catch (ArgumentException ex) when (ex.Message.Contains("target")) {
    // fall back to default page or show message
}

Prevention

When it happens

Trigger: Clicking a Hyperlink whose NavigateUri is null/empty or whose target (e.g. relative pack URI or named element/fragment) cannot be resolved by the hosting NavigationService in OnRequestNavigate.

Common situations: Relative pack URIs in a page hosted without a proper Application/Frame context; typos in NavigateUri; hyperlinks placed in surfaces (e.g. certain popups/controls) without navigation container; missing base URI for relative resolution.

Understand the failure class

Background: "Invalid URL" / "URL cannot be empty": fix the malformed or missing URL behind request-construction failures — this error's family across 50 libraries.

Related errors

AI-assisted analysis of dotnet/wpf@81131a70a4 (2026-09-14). Data as JSON: /api/errors/cbf67f69e5c07cdb. Report an issue: GitHub.

Appendix: source

Thrown at src/Microsoft.DotNet.Wpf/src/PresentationFramework/System/Windows/Navigation/NavigationService.cs:205

            {
                if (inSameThread)
                {
                    navigator.Navigate(bpu);
                }
                else
                {
                    ((DispatcherObject)navigator).Dispatcher.BeginInvoke(
                                DispatcherPriority.Send,
                                (DispatcherOperationCallback)delegate(object unused)
                                {
                                    return navigator.Navigate(bpu);
                                },
                                null);
                }
            }
            else
            {
                throw new System.ArgumentException(SR.HyperLinkTargetNotFound);
            }
        }

        // Tests if two uris resolve to the same Uri.  The Uri fragments are also
        // compared.  Neither comparison is case sensitive.
        private static bool IsSameUri(Uri baseUri, Uri a, Uri b, bool withFragment)
        {
            if (object.ReferenceEquals(a, b)) // also handles both null
            {
                return true;
            }
            if (a == null || b == null)
            {
                return false;
            }

            Uri aResolved = BindUriHelper.GetResolvedUri(baseUri, a);
            Uri bResolved = BindUriHelper.GetResolvedUri(baseUri, b);

View on GitHub (pinned to 81131a70a4)