Question: In preview all good, but when I compiling, there is no image. If problem in source, so why it is showing in preview window?
![preview](https://i.stack.imgur.com/ZY4fQ.png)

![error](https://i.stack.imgur.com/HxRyF.png)

```
 <Grid>
    <!-- Grid 4x3 -->
    <Grid.RowDefinitions>
        <RowDefinition Height="1*"></RowDefinition>
        <RowDefinition Height="0.5*"></RowDefinition>
        <RowDefinition Height="0.5*"></RowDefinition>
        <RowDefinition Height="0.7*"></RowDefinition>
    </Grid.RowDefinitions>

    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="0.2*"></ColumnDefinition>
        <ColumnDefinition Width="1*"></ColumnDefinition>
        <ColumnDefinition Width="0.2*"></ColumnDefinition>
    </Grid.ColumnDefinitions>

    <!-- Controls -->
        <!-- Row №1-->
    <Image Grid.Row="0" Grid.Column="1" Source="pack://siteoforigin:,,,/Resources/logo.png"></Image>
        <!-- Row №2-3 -->
    <StackPanel Grid.Row="1" Grid.Column="1" Grid.RowSpan="2">
        <Label Content="Вы заходите как..."></Label>
        <ComboBox>
            <ComboBoxItem Content="Клиент"></ComboBoxItem>
            <ComboBoxItem Content="Сотрудник"></ComboBoxItem>
        </ComboBox>
        <Label Content="ID"></Label>
        <TextBox></TextBox>
        <Label Content="Пароль"></Label>
        <PasswordBox></PasswordBox>
    </StackPanel>
    <!-- Row №4 -->
</Grid>

```

Answer: 
Seems that the image you specified is not copied to the output directory. You can resolve the issue in two ways:  

1) In the property grid set Build Action to "None" and Copy to Output Directory to "Copy always" (you need to do this because the siteoforigin URI seeks the resource in the binary file location)  

2) Set the Build Action property to "Resource" and use the `pack://application` absolute URI or the relative URI (like this: `<Image Source="Resources/logo.png"/>` )
Try to set source as this and see if it solve your problem.

```
<Image Source="/MonFitClub;component/Resources/logo.png"/>

```

where if i did see corectly `MonFitClub` is name od your Project.