dotnet/wpf · error · XpsSerializationException

SR.ReachSerialization_NoSerializer

Error message

SR.ReachSerialization_NoSerializer

What it means

XpsSerializationException thrown by NGCUIElementCollectionSerializerAsync.SerializeUIElement when the serialization manager cannot find any registered serializer capable of serializing the given Visual/UIElement. During XPS writing every element in the collection must have a matching serializer; if the lookup returns null the element type is unsupported.

Solutions

1. Replace or wrap the unsupported element with a supported type (e.g. render the custom visual into a DrawingVisual/RenderTargetBitmap that the XPS writer accepts).
2. Check which element type has no serializer by inspecting the element passed to SerializeUIElement (visual.GetType()).
3. Ensure you use the standard document structure (FixedDocument/FixedPage) so elements are serialized through supported paths.
4. If a custom serializer exists, register it with the serialization manager before serialization begins.

Example fix

// before
panel.Children.Add(new MyCustomControl()); // no serializer registered
// after
var bmp = RenderToBitmap(myCustomControl); // rasterize to a supported visual
panel.Children.Add(new Image { Source = bmp });

foreach (var child in visualTree)
    if (!IsFrameworkSupportedForXps(child.GetType()))
        throw new NotSupportedException($"No XPS serializer for {child.GetType()}");

static bool HasXpsSerializer(Visual v) =>
    v is FixedPage || v is PageContent || v is DrawingVisual == false && v.GetType().Namespace.StartsWith("System.Windows");

try { SerializeNextUIElement(element); }
catch (XpsSerializationException ex) when (ex.Message.Contains("NoSerializer"))
{ /* rasterize element to bitmap and continue */ }

When it happens

Trigger: Iterating a UIElementCollection during XPS serialization and encountering an element type (custom Visual, third-party control, unsupported DrawingVisual variant) for which SerializerManager has no registered serializer.

Common situations: Exporting a WPF visual tree to XPS that contains custom or third-party controls not handled by the framework's serializer table; using elements introduced in newer framework versions with an older serialization path; printing visuals that bypass the standard document structure.

Understand the failure class

Background: UnsupportedOperationException and "is not supported" errors: when a library deliberately refuses a call — this error's family across 30 libraries.

Related errors

• Cannot find the appropriate serializer.
• Cannot find the appropriate serializer.
• SR.ReachSerialization_NoSerializer
• SR.ReachSerialization_NoSerializer
• SR.ReachSerialization_NoSerializer

AI-assisted analysis of dotnet/wpf@81131a70a4 (2026-09-14). Data as JSON: /api/errors/91b41d6a997dd927. Report an issue: GitHub.

Appendix: source

Thrown at src/Microsoft.DotNet.Wpf/src/ReachFramework/Serialization/manager/NGCUIElementCollectionSerializerAsync.cs:212

        private 
        void 
        SerializeUIElement(
            object uiElement
            )
        {
            Visual visual = uiElement as Visual;

            if(visual != null)
            {
                ReachSerializer serializer = SerializationManager.GetSerializer(visual);

                if(serializer!=null)
                {
                    serializer.SerializeObject(visual);
                }
                else
                {
                    throw new XpsSerializationException(SR.ReachSerialization_NoSerializer);
                }
            }
        }

        #endregion Private Methods
    };

    internal class NgcUIElementCollectionSerializerContext :
                   NGCSerializerContext
    {
        public
        NgcUIElementCollectionSerializerContext(
            NGCSerializerAsync          serializer,
            SerializableObjectContext   objectContext,
            IEnumerator                 enumerator,
            SerializerAction            action
            ):
            base(serializer,objectContext,action)

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