Wpf ComboBox throws exception on combobox in windows 7

Question

I made a WPF application (Framework 4.5) on Windows 8 which uses usual comboboxes and some other controls. The problem I am facing is that it crashes on Windows 7:

A first chance exception of type System.Windows.Markup.XamlParseException occurred in PresentationFramework.dll
Additional information: 'Initialization of 'System.Windows.Controls.ComboBox' threw an exception.'

Here is my XAML for combobox:

 <ComboBox Name="bloodGroupList" Grid.Row="7" Grid.Column="1"
         SelectedIndex="{Binding Patient.BloodGroup, Converter={StaticResource StrToBlood}, Mode=TwoWay}"
         IsEnabled="{Binding IsEditing}"
         VerticalAlignment="Center" Margin="5,5.5" VerticalContentAlignment="Center"
         BorderThickness="0" Height="22" TabIndex="4" HorizontalContentAlignment="Stretch">
    <ComboBoxItem Content="A+" />
    <ComboBoxItem Content="A-" />
    <ComboBoxItem Content="B+" />
    <ComboBoxItem Content="B-" />
    <ComboBoxItem Content="O+" />
    <ComboBoxItem Content="O-" />
    <ComboBoxItem Content="AB+" />
    <ComboBoxItem Content="AB-" />
</ComboBox>

I read on some blog to run this fix NDP45-KB2750147-x64 but it says:

Software Update KB2750147 Installation Wizard does not apply, or is blocked by another condition on your computer. Please click the link below for more details.

Answer 1

I put this in the App.xaml.cs file to get the full stack trace. This might be a useful way for you to troubleshoot problems.

using System;
using System.Diagnostics;
using System.IO;
using System.Windows;
using System.Windows.Threading;

public partial class App : Application
{
    void App_DispatcherUnhandledException(object sender, DispatcherUnhandledExceptionEventArgs e)
    {
        // All unhandled exceptions come here. A stacktrace is saved as a text file with date and time.

        StackTrace st = new StackTrace(e.Exception);
        string fileName = DateTime.Now.ToString().Replace('/', '-').Replace(':', '-') + " errors.txt";
        fileName = @"C:\Users\Public\" + fileName;
        System.Windows.MessageBox.Show("Critical Error. Closing program.\nStacktrace can be found:" + fileName);
        using (var stream = new FileStream(fileName, FileMode.OpenOrCreate))
        {
            using (var strWrite = new StreamWriter(stream))
            {
                strWrite.Write(st.ToString());
            }
        }

        if (MainWindow != null)
        {
            MainWindow.Close();
        }
        else
        {
            Environment.Exit(0);
        }

        e.Handled = true;
    }
}