Import exception

So i am working on the same WPF project on two different computers.

I am using bitbucket (git) to push and pull to an online repository.

Now ive just collected the project on a new computer and want to run the program. but i get the following error:

The invocation of the constructor on type 'Henvendelser.MainWindow' 
that matches the specified binding constraints threw an exception.' 
Line number '5' and line position '9'.

now this is my XML:

<Window x:Class="Henvendelser.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:DV="clr-namespace:System.Windows.Controls.DataVisualization;assembly=System.Windows.Controls.DataVisualization.Toolkit"
    xmlns:CHART="clr-namespace:System.Windows.Controls.DataVisualization.Charting;assembly=System.Windows.Controls.DataVisualization.Toolkit"
    Title="Henvendelser" Height="699" Width="888">
<Grid>

    <TabControl 
        Name="tabControl1"
        Margin="0,61,0,0">
        <TabItem
            Header="Henvendelser" 
            Name="tabItem1">

                <CHART:Chart
                         Name="Henvendelser"
                         Background="LightSteelBlue" 
                         Title="Henvendelser"
                         FlowDirection="RightToLeft" 
                         FontFamily="Calibri" 
                         Visibility="Visible" Height="412">

                <CHART:Chart.Series>
                    <CHART:LineSeries
                                IndependentValueBinding="{Binding Path=Key}"
                                DependentValueBinding="{Binding Path=Value}"  AnimationSequence="FirstToLast">
                    </CHART:LineSeries>
                    <CHART:LineSeries
                                IndependentValueBinding="{Binding Path=Key}"
                                DependentValueBinding="{Binding Path=Value}"  AnimationSequence="FirstToLast">
                    </CHART:LineSeries>
                </CHART:Chart.Series>
            </CHART:Chart>
        </TabItem>
    </TabControl>
    <Button Content="Hent Data" Height="55" HorizontalAlignment="Left" Margin="744,12,0,0" Name="btn_hentData" VerticalAlignment="Top" Width="102"/>
    <DataGrid AutoGenerateColumns="False" Height="100" HorizontalAlignment="Left" Margin="119,560,0,0" Name="dataGrid1" VerticalAlignment="Top" Width="727"  />
</Grid>

This is line 5:

xmlns:CHART="clr-namespace:System.Windows.Controls.DataVisualization.Charting;assembly=System.Windows.Controls.DataVisualization.Toolkit"

now at first i thought it was the imports so i tried to import all of the DLL files again but with no result

this is a picture of my References

Can anyone tell me why i am getting this execption and how i can get rid of it?

** Additional information**

The funny thing about this error and its location is that i am actually able to see the chart area in my GUI builder even though its my chart import there is a problem with.

Here is a picture: