WPF FileLoadException: Could not load file or assembly. A strongly-named assembly is required

I am doing a WPF .net framework appplication.When i run this code,Exception thrown.

here i am calling UIOrderclass xaml file in AddUiorder.

UIorderClass.cs

namespace UIorder:UserControl
{
  public partial class UIorderClass
    {
  public UIorderClass()
        {
            InitializeComponent();
        }
//some logic part here
}
}

UIorderClass.xaml

 <UserControl x:Class="UIorder.UIorderClass"
        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"
<Grid>
//some UI components here
</Grid>

AddUIorderClass.XAML

<Window x:Class="View.AddUIorderClass"
        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"
        mc:Ignorable="d"
       xmlns:add="clr-namespace:UIorder;assembly=UIorder"

<Grid>
//some UI code here
</Grid>
</Window>

AddUIorderClass.cs

{
  
    public partial class AddUIorderClass : Window
    {
        public AddUIorderClass()
        {
            InitializeComponent();
        }
//code here
}
}

Error message is shown a as below

FileLoadException: Could not load file or assembly 'UIorder, Culture=neutral, PublicKeyToken=null' or one of its dependencies. A strongly-named assembly is required. (Exception from HRESULT: 0x80131044)