Hello Emmanuel,

Has this issue been resolved?

I received the same error message with WPF DV 10.2 in Visual Studio 2010 when I was doing trial license expiration testing.  I was able to solve the problem by deleting all content in the licenses.licx file.  This file should be located in your project folder under the Properties subfolder.

This might be a different issue than you experienced, as I was advised that this is a common error message in .NET.  I would suggest backing up the licenses.licx file and then deleting all content.

Elizabeth Albert

Localization Engineer

Unfortunately, I'm not setting the datacontext in XAML.  I just have a series defined - see below.
As soon as I add the user control below to a window, Blend does not render with window and displays the exception:

    "Getting the "enumerator is not valid because the collection changed"

Emmanuel

<UserControl
  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:igCA="http://infragistics.com/Chart"
  x:Class="ucMetricProduction"
  Background="#FFD6E6FA"
  FontFamily="Arial"
    FontSize="11"
  mc:Ignorable="d">

  <UserControl.Resources>
    <ResourceDictionary>
      <ResourceDictionary.MergedDictionaries>
        <ResourceDictionary Source="Resources/infragistics/Brushes.xaml"/>
        <ResourceDictionary Source="Resources/infragistics/Carousel.xaml"/>
        <ResourceDictionary Source="Resources/infragistics/Frame.xaml"/>
        <ResourceDictionary Source="Resources/infragistics/Tabs.xaml"/>
        <ResourceDictionary Source="Resources/infragistics/Misc.xaml"/>
        <ResourceDictionary Source="Resources/infragistics/Buttons.xaml"/>
        <ResourceDictionary Source="Resources/infragistics/xamChart/Default/Chart2D.xaml"/>
      </ResourceDictionary.MergedDictionaries>
    </ResourceDictionary>
  </UserControl.Resources>

  <Border BorderBrush="#FFFFFFFF" BorderThickness="1,1,1,1" IsEnabled="True">
    <Grid>

      <Grid.RowDefinitions>
        <RowDefinition Height="*"/>
      </Grid.RowDefinitions>

      <!-- Chart control -->
      <igCA:XamChart x:Name="xcChart1" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Grid.Row="0"
                       StartPaletteBrush="#FF076CB0"  >
        <!-- Legend -->
        <igCA:XamChart.Legend>
          <igCA:Legend Visible="False"/>
        </igCA:XamChart.Legend>
        <!-- Scene -->
        <igCA:XamChart.Scene>
          <igCA:Scene BorderBrush="Black">
            <igCA:Scene.GridArea>
              <igCA:GridArea Style="{StaticResource GridAreaStyle}"/>
            </igCA:Scene.GridArea>
          </igCA:Scene>
        </igCA:XamChart.Scene>
        <!-- Data points -->
        <igCA:XamChart.Series>
          <igCA:Series Label="Funded" ChartType="stackedColumn" >
            <igCA:Series.DataPoints>
              <igCA:DataPoint Value="2.6" Label="Nov"/>
              <igCA:DataPoint Value="2.5" Label="Dec"/>
              <igCA:DataPoint Value="3.3" Label="Jan"/>
              <igCA:DataPoint Value="1.6" Label="Feb"/>
              <igCA:DataPoint Value="0" Label="Mar"/>
            </igCA:Series.DataPoints>
            <igCA:Series.Animation>
              <igCA:Animation BeginTime="00:00:01"/>
            </igCA:Series.Animation>
          </igCA:Series>
          <!-- Data points -->
          <igCA:Series Label="Projected" ChartType="stackedColumn" UseDataTemplate="True">
            <igCA:Series.DataPoints>
              <igCA:DataPoint Value="0"/>
              <igCA:DataPoint Value="0"/>
              <igCA:DataPoint Value="0"/>
              <igCA:DataPoint Value="1"/>
              <igCA:DataPoint Value="3"/>
            </igCA:Series.DataPoints>
            <igCA:Series.Animation>
              <igCA:Animation BeginTime="00:00:02"/>
            </igCA:Series.Animation>
          </igCA:Series>
        </igCA:XamChart.Series>
        <!-- Axes -->
        <igCA:XamChart.Axes>
          <igCA:Axis
            AxisType="PrimaryX"
            Animation="{StaticResource AxisAnimation}"
            MajorGridline="{StaticResource AnimationMarkX}"
            Label="{StaticResource AnimationLabelsX}"/>
          <igCA:Axis
            AxisType="PrimaryY"
            Animation="{StaticResource AxisAnimation}"
            MajorGridline="{StaticResource AnimationMarkY}"
            Label="{StaticResource AnimationLabelsY}">
            <igCA:Axis.Stripes>
              <igCA:Stripe Style="{StaticResource StripeStyle}"/>
            </igCA:Axis.Stripes>
          </igCA:Axis>
        </igCA:XamChart.Axes>
        <igCA:XamChart.Caption>
          <igCA:Caption FontFamily="Arial" FontSize="16" FontStretch="Expanded" FontWeight="SemiBold" Text="Title Here" />
        </igCA:XamChart.Caption>
      </igCA:XamChart>

      <Grid x:Name="grdButtons" HorizontalAlignment="Left" Height="30" VerticalAlignment="Top" Background="#4C333333">
        <Grid.ColumnDefinitions>
          <ColumnDefinition Width="0.33*"/>
          <ColumnDefinition Width="0.33*"/>
          <ColumnDefinition Width="0.933*"/>
        </Grid.ColumnDefinitions>
        <Border Grid.ColumnSpan="3" BorderThickness="1,1,1,1" BorderBrush="#9FFFFFFF"/>
        <ToggleButton x:Name="tgb1" Content="L" Cursor="Hand"
                      FontWeight="Normal" FontSize="10" Margin="1,0,1,0" d:LayoutOverrides="GridBox" ToolTip="By Loan volume" Width="18" Height="18" IsChecked="True"/>
        <ToggleButton x:Name="tgb2" Content="#" Cursor="Hand"
                      FontWeight="Normal" FontSize="10" ToolTip="By number of Loans" Grid.Column="1" Grid.ColumnSpan="1" Margin="1,0,1,0" Width="18" Height="18"/>
        <ToggleButton x:Name="tgb3" Content="$" Width="18" Cursor="Hand"
                      FontWeight="Normal" FontSize="10" Margin="1,0,1,0" HorizontalAlignment="Left" ToolTip="By Commission" Grid.Column="2" Height="18"/>
      </Grid>
      <Rectangle Opacity="0.595" Fill="#A7FFFFFF" Stroke="{x:Null}" HorizontalAlignment="Stretch" Margin="0,30,0,0" VerticalAlignment="Stretch" Visibility="Hidden" x:Name="recCover" Panel.ZIndex="2"/>
      <TextBlock VerticalAlignment="Bottom" Text="Sample" TextWrapping="Wrap" Margin="0,0,0,65" Padding="0,0,4,0"
                 x:Name="tbSample" Panel.ZIndex="3" HorizontalAlignment="Center" FontSize="36" FontWeight="Normal" FontStyle="Italic"
                 RenderTransformOrigin="0.5,0.5" TextDecorations="Underline" Visibility="Hidden">
          <TextBlock.RenderTransform>
              <TransformGroup>
                  <ScaleTransform ScaleX="1" ScaleY="1"/>
                  <SkewTransform AngleX="0" AngleY="0"/>
                  <RotateTransform Angle="-29"/>
                  <TranslateTransform X="0" Y="0"/>
              </TransformGroup>
          </TextBlock.RenderTransform>
          <TextBlock.Foreground>
              <SolidColorBrush Color="{DynamicResource colorExcludedChanged}"/>
          </TextBlock.Foreground>
      </TextBlock>

    </Grid>
  </Border>
</UserControl>

Hey, I feel your pain.

The solution, I found, is that you should not set the DataContext in Xaml.  You can set the DataContext in the C# code behind at will.

Let me know if that helps.

I hope it does.

I am having the same issue - getting the "enumerator is not valid because the collection changed" exception in Blend.

I have a XamChart with two of series of ChartType = "stackedColumn" hosted inside a user control.  Whenever I add the user control to a window, Blend stops rendering the window and shows the error above. 

The funny thing is that I have another XamChart with one series of ChartType = "bar" hosted inside another user control - and there are no problems with that one.

I will open a ticket with support, but it would be great if the workarounds were posted here - it's a lot faster to get the information.