[PresentationFramework]System.Windows.Markup.XamlParseException

John,

I am seeing what appears to be the same issue.  Did you figure out what causes this problem?

In my case the exception consistently occurs on the second and every subsequent run of my test case until I restart my application.

I've noticed that whatever XAML property appears first in my markup is the target of the error.  For example, in the XAML snippet below, Height is the first property to be assigned, but if I change Width to be first then the same exception occurs but complaining about width.  I also experimented with a variety of values and the exact assignment value doesn't seem to matter.

<UserControl x:Class="..."
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Height="Auto" Width="Auto" MinHeight="300" MinWidth="300" Padding="20">
<TextBlock Name="TextBox" HorizontalAlignment="Center" VerticalAlignment="Center" TextAlignment="Center" TextWrapping="Wrap" />
</UserControl>

// Need this DllImport statement to reset the floating point register below
[DllImport("msvcr71.dll", CallingConvention = CallingConvention.Cdecl)]
private static extern int _controlfp(int n, int mask);

void useThirdPartyWithFPSideEffects() {
    try {
        //use the library
    }
    catch (Exception ex) {
        //do what you need to do
    }
    finally {
        //misc cleanup

        //reset the floating point register to avoid fp side-effect of library
        _controlfp(0x9001F, 0xFFFFF); // restore floating-point register to default value required by .NET Framework
    }
}