dotnet/wpf · error · COMException

0x80070057

0x80070057

Error message

SR.TextStore_BadObject

What it means

InsertEmbedded's obj parameter must implement IComDataObject (the COM IDataObject). TextStore casts with 'obj as IComDataObject' and throws COMException with E_INVALIDARG (0x80070057) and SR.TextStore_BadObject when the cast fails, i.e. the caller passed an object that is not a COM data object.

Solutions

1. Pass an object implementing IComDataObject (COM IDataObject) to InsertEmbedded.
2. Wrap managed data with the appropriate COM-callable wrapper before the call.
3. Null-check and type-check the object client-side before invoking InsertEmbedded.

Example fix

// before
store.InsertEmbedded(flags, start, end, new DataObject(), out change);
// after
IComDataObject comData = /* COM IDataObject instance */;
store.InsertEmbedded(flags, start, end, comData, out change);

if (obj is IComDataObject data) { store.InsertEmbedded(flags, start, end, data, out change); }

bool IsComDataObject(object o) => o is IComDataObject;

try { store.InsertEmbedded(...); } catch (COMException ex) when (ex.ErrorCode == unchecked((int)0x80070057)) { /* wrong data object type */ }

When it happens

Trigger: A TSF client calls InsertEmbedded passing a managed System.Windows.DataObject, arbitrary object, or null instead of a COM IComDataObject/IDataObject instance.

Common situations: Interop code conflating managed DataObject with the COM IDataObject; passing the wrong data-object wrapper type across the TSF boundary.

Understand the failure class

Background: Type mismatch errors: IllegalArgumentException, TypeError and type guards across 150 open-source libraries — this error's family across 150 libraries.

Related errors

• ' ' is not a Visual or Visual3D.
• 0x80004001
• 0x80004002
• 0x80004005
• 0x80040200

AI-assisted analysis of dotnet/wpf@81131a70a4 (2026-09-14). Data as JSON: /api/errors/f61fd5f428ac5b70. Report an issue: GitHub.

Appendix: source

Thrown at src/Microsoft.DotNet.Wpf/src/PresentationFramework/System/Windows/Documents/TextStore.cs:626

            // Disable embedded object temporarily.
#if ENABLE_INK_EMBEDDING
            if (!TextSelection.HasConcreteTextContainer)
            {
                throw new COMException(SR.TextStore_TS_E_FORMAT, UnsafeNativeMethods.TS_E_FORMAT);
            }

            TextContainer container;
            TextPointer startPosition;
            TextPointer endPosition;
            IComDataObject data;

            // The object must have IOldDataObject internface.
            // The obj param of InsertEmbedded is IDataObject in Win32 definition.
            data = obj as IComDataObject;
            if (data == null)
            {
                throw new COMException(SR.TextStore_BadObject, NativeMethods.E_INVALIDARG);
            }

            container = (TextContainer)this.TextContainer;

            startPosition = container.CreatePointerAtOffset(startIndex, LogicalDirection.Backward);
            endPosition = container.CreatePointerAtOffset(endIndex, LogicalDirection.Forward);

            InsertEmbeddedAtRange(startPosition, endPosition, data, out change);
#else
            throw new COMException(SR.TextStore_TS_E_FORMAT, UnsafeNativeMethods.TS_E_FORMAT);
#endif
        }

        // See msdn's ITextStoreACP documentation for a full description.
        public void InsertTextAtSelection(UnsafeNativeMethods.InsertAtSelectionFlags flags, char[] text, int cch, out int startIndex, out int endIndex, out UnsafeNativeMethods.TS_TEXTCHANGE change)
        {
            ITextPointer startNavigator;
            ITextPointer endNavigator;

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