What could possibly cause COMExceptions while dragging file over the Desktop?

Question

It doesn't crash, all the exceptions I mention here can only be seen in Output window of Visual Studio. Here is the implementation of Dragging:
WPF:

<StackPanel Orientation="Vertical"
            MouseDown="DragShortcut"
            x:Name="Shortcut">
    <Image Source="{Binding Icon}"/>
    <Label Content="{Binding ShortcutLabel}"/>
</StackPanel>

cs code:

private void DragShortcut(object sender, MouseButtonEventArgs e)
{
    if (e.LeftButton != MouseButtonState.Pressed)
        return;

    var dataObject = new DataObject(DataFormats.FileDrop, new[] { Options.DragDropOptions.ShortcutPath });
    DragDrop.DoDragDrop(Shortcut, dataObject, DragDropEffects.Copy);
}

Everything seems to work as expected, but every time I drag something over my Desktop or Explorer window I receive the following messages in the Output window of my Visual Studio:

...
A first chance exception of type 'System.Runtime.InteropServices.COMException' occurred in PresentationCore.dll
A first chance exception of type 'System.Runtime.InteropServices.COMException' occurred in PresentationCore.dll
A first chance exception of type 'System.Runtime.InteropServices.COMException' occurred in PresentationCore.dll
A first chance exception of type 'System.Runtime.InteropServices.COMException' occurred in PresentationCore.dll
A first chance exception of type 'System.NotImplementedException' occurred in PresentationCore.dll
A first chance exception of type 'System.Runtime.InteropServices.COMException' occurred in PresentationCore.dll
... 

When Visual Studio is set to stop on that kind of exceptions, I can see the following Exceptions:

System.Runtime.InteropServices.COMException was unhandled
Message: An exception of type 'System.Runtime.InteropServices.COMException' occurred in PresentationCore.dll and wasn't handled before a managed/native boundary
Additional information: Invalid FORMATETC-Structure (Exception HRESULT: 0x80040064 (DV_E_FORMATETC))

and

System.NotImplementedException was unhandled
Message: An exception of type 'System.NotImplementedException' occurred in PresentationCore.dll and wasn't handled before a managed/native boundary
Additional information: The method or operation is not implemented.

It doesn't lead to crash or anything, it's just uncomfortable for me as a developer to have such a thing happening in background. Does anyone have an Idea what could it be?

EDIT:
This problem looks a lot like mine, but seems to have another cause and solution.

Afterbrain

Possible duplicate of How to avoid a System.Runtime.InteropServices.COMException? – Citrin

@Citrin the exception is similar, although in my case it seems to have another cause. – Afterbrain

Answer 1

This is entirely normal. Whatever window of another process you drag over will make that process poke the object you drag to see if it supports a particular format or can convert the object to another format. Done with COM calls under the hood. If the answer is "yes" then you see the cursor change to indicate that you can drop.

The IDataObject interface implementation in WPF says "no" by throwing an exception. The normal way in which COM failure codes are generated in a .NET program. That exception gets converted by the CLR into a COM error code, an HRESULT, to tell the process that it isn't going to work. Note how the Exeption class has the HResult property, that's what the process sees.

The debugger dutifully displays the "first chance" exception notification if you asked for it. Right-click the Output window, "Exception Messages" option, turned on by default. Nothing actually goes wrong, the exception is caught and handled gracefully. Feature, not a bug.

Godbey