WPF 7.net app craching after it is done building

System.Windows.Markup.XamlParseException: ''The invocation of the constructor on type 'mythos.MainWindow' that matches the specified binding constraints threw an exception.' Line number '7' and line position '9'.'

<Window x:Class="mythos.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:mythos"
        xmlns:viewModel="clr-namespace:mythos.MVVM.ViewModel"
        mc:Ignorable="d"
        Height="900" Width="1015"
        WindowStyle="None"
        ResizeMode="CanResizeWithGrip"
        Background="Transparent"
        AllowsTransparency="True" IsManipulationEnabled="True">

    <Window.DataContext>
        <viewModel:MainViewModel/>
    </Window.DataContext>