Application crashed with unhandled exception "Layout cycle detected. Layout could not complete."

[harvinders]

Describe the bug Not sure if I have enough information, but one of my applications crashed with the following exception. I thought it is something that the team would like to know. I have never seen such exception before.

My application has a ListView and the ListItems has few ItemsRepeater.

I would add more information if I see it happen again.

	Name	Value	Type
◢	e	{Windows.UI.Xaml.UnhandledExceptionEventArgs}	Windows.UI.Xaml.UnhandledExceptionEventArgs
	◢ Exception	{"A cycle occurred while laying out the GUI."}	System.Exception {Windows.UI.Xaml.LayoutCycleException}
	▶ Data	{System.Collections.ListDictionaryInternal}	System.Collections.IDictionary {System.Collections.ListDictionaryInternal}
	HResult	-2144665580	int
	HelpLink	null	string
	IPForWatsonBuckets	0x00000000	System.UIntPtr
	▶ InnerException	null	System.Exception
	IsTransient	false	bool
	Message	"A cycle occurred while laying out the GUI."	string
	RemoteStackTrace	null	string
	Source	null	string
	StackTrace	null	string
	TargetSite	null	System.Reflection.MethodBase
	WatsonBuckets	null	object
	_HResult	-2144665580	int
	_className	null	string
	▶ _data	{System.Collections.ListDictionaryInternal}	System.Collections.IDictionary {System.Collections.ListDictionaryInternal}
	_dynamicMethods	null	object
	_exceptionMethod	null	System.Reflection.MethodBase
	_helpURL	null	string
	▶ _innerException	null	System.Exception
	_ipForWatsonBuckets	0x00000000	System.UIntPtr
	_message	"A cycle occurred while laying out the GUI."	string
	_remoteStackIndex	0	int
	_remoteStackTraceString	null	string
	_source	null	string
	_stackTrace	null	object
	_stackTraceString	null	string
	_watsonBuckets	null	object
	_xcode	-532462766	int
	_xptrs	0x00000000	System.IntPtr
	▶ Static members

Version Info

NuGet package version: Microsoft.UI.Xaml 2.6.0-prerelease

Windows app type:

UWP	Win32
Yes

Windows 10 version	Saw the problem?
Insider Build (xxxxx)
May 2020 Update (19041)
November 2019 Update (18363)	Yes
May 2019 Update (18362)
October 2018 Update (17763)
April 2018 Update (17134)
Fall Creators Update (16299)
Creators Update (15063)

Device form factor	Saw the problem?
Desktop
Xbox
Surface Hub
IoT

Additional context

[beervoley]

@harvinders do you by any chance have a ListView or ItemsRepeater inside ListView wrapped into ScrollViewer?

[harvinders]

No @beervoley , I am not using ScrollViewer, as I kept the top most control as ListView following is my XAML files. The issue manifests when I scroll the ListView couple of times. Also, the application uses ReactiveUI for bindings in code behind, hence you would not see all the bindings in the XAML files.

MainPage.xaml

    <Grid x:Name="ContentArea" Margin="{StaticResource MediumLeftRightMargin}">
        <Grid Background="{ThemeResource SystemControlPageBackgroundChromeLowBrush}" RowSpacing="12">
            <Grid.RowDefinitions>
                <RowDefinition Height="Auto"/>
                <RowDefinition Height="12"/>
                <RowDefinition Height="Auto"/>
                <RowDefinition/>
            </Grid.RowDefinitions>
            <AutoSuggestBox Grid.Row="0" Width="300" x:Name="SearchBox" CornerRadius="8" HorizontalAlignment="Center" FontSize="{StaticResource XLargeFontSize}" QueryIcon="Find"/>
            <muxc:ProgressBar
                x:Name="ProgressBar"
                Grid.Row="1"
                Margin="{StaticResource SmallLeftRightMargin}"
                IsIndeterminate="True"
                VerticalAlignment="Center"
                HorizontalAlignment="Stretch" />
            <muxc:ItemsRepeater Grid.Row="2" x:Name="SuggestionList">
                <muxc:ItemsRepeater.Layout>
                    <muxc:StackLayout Orientation="Horizontal" Spacing="8"/>
                </muxc:ItemsRepeater.Layout>
                <DataTemplate x:DataType="system:String">
                    <HyperlinkButton Content="{x:Bind Mode=OneWay}" FontSize="{StaticResource XMediumFontSize}" />
                </DataTemplate>
            </muxc:ItemsRepeater>
            <ListView Grid.Row="3" x:Name="MeaningList" SelectionMode="None">
                <ListView.ItemTemplate>
                    <DataTemplate x:DataType="core:Meaning">
                        <views:MeaningView HorizontalAlignment="Stretch" ViewModel="{x:Bind Mode=OneWay}" />
                    </DataTemplate>
                </ListView.ItemTemplate>
                <ListView.ItemContainerStyle>
                    <Style TargetType="ListViewItem">
                        <Setter Property="HorizontalContentAlignment" Value="Stretch" />
                    </Style>
                </ListView.ItemContainerStyle>

            </ListView>
        </Grid>
    </Grid>

MeaningView.xaml

<UserControl
    x:Class="Words.Views.MeaningView"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:Words.Views"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:controls="using:Microsoft.UI.Xaml.Controls"
    xmlns:core="using:Words.Core"
    xmlns:system="using:System"
    xmlns:controls1="using:Microsoft.Toolkit.Uwp.UI.Controls"
    mc:Ignorable="d">

    <Grid RowSpacing="8">
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>
        </Grid.RowDefinitions>
        <StackPanel Orientation="Horizontal" Spacing="16">
            <RichTextBlock Typography.StylisticSet4="True" FontFamily="Cambria">
                <Paragraph>
                    <Run x:Name="PartOfSpeech" Foreground="DarkRed" FontSize="{StaticResource LargeFontSize}"/>
                    <Run x:Name="Word" FontSize="{StaticResource XLargeFontSize}"/>
                </Paragraph>
            </RichTextBlock>
            <AppBarButton Icon="Add" VerticalAlignment="Bottom" Style="{StaticResource AppBarButtonStyle}" LabelPosition="Collapsed"/>
        </StackPanel>

        <controls:ItemsRepeater Grid.Row="1" x:Name="PronunciationList">
            <controls:ItemsRepeater.Layout>
                <controls:StackLayout Orientation="Horizontal" Spacing="8"/>
            </controls:ItemsRepeater.Layout>
            <DataTemplate x:DataType="core:Phonetic">
                <local:PronunciationView ViewModel="{x:Bind Mode=OneWay}"/>
            </DataTemplate>
        </controls:ItemsRepeater>

        <controls:ItemsRepeater Grid.Row="2" x:Name="DefinitionList">
            <DataTemplate x:DataType="core:Definition">
                <Grid RowSpacing="8" Margin="0 6">
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="30"/>
                        <ColumnDefinition/>
                    </Grid.ColumnDefinitions>
                    <Grid.RowDefinitions>
                        <RowDefinition Height="Auto"/>
                        <RowDefinition Height="Auto"/>
                        <RowDefinition Height="Auto"/>
                    </Grid.RowDefinitions>
                    <TextBlock Text="{x:Bind Sn}" FontSize="{StaticResource XMediumFontSize}"/>
                    <TextBlock Grid.Column="1" Text="{x:Bind DefinitionDefinition}" TextWrapping="WrapWholeWords" FontSize="{StaticResource XMediumFontSize}"/>
                    <TextBlock Grid.Column="1" Grid.Row="1" Text="{x:Bind Example}" TextWrapping="WrapWholeWords" FontSize="{StaticResource XMediumFontSize}" Foreground="{ThemeResource SystemControlHighlightAccentBrush}"/>
                    <controls:ItemsRepeater Grid.Column="1" Grid.Row="2" ItemsSource="{x:Bind Synonyms}" >
                        <controls:ItemsRepeater.Layout>
                            <controls:StackLayout Orientation="Horizontal" />
                        </controls:ItemsRepeater.Layout>
                        <DataTemplate x:DataType="system:String">
                            <HyperlinkButton Content="{x:Bind Mode=OneWay}" FontSize="{StaticResource XMediumFontSize}" />
                        </DataTemplate>
                    </controls:ItemsRepeater>
                </Grid>
            </DataTemplate>
        </controls:ItemsRepeater>
    </Grid>
</UserControl>

Also, after adding <controls:ItemsRepeater Grid.Column="1" Grid.Row="2" ItemsSource="{x:Bind Synonyms}" > the scrolling performance was also very bad.

[harvinders]

@beervoley Changing the layout to WrapLayout from windows community toolkit improved the performance and I am not seeing another crash, it may happen I might have to stress the app a little more.

<controls:ItemsRepeater.Layout>
   <uct:WrapLayout Orientation="Horizontal" />
</controls:ItemsRepeater.Layout>

[beervoley]

@harvinders that's interesting, I have never seen this issue before. I will try to have a look during the week :)

[99067718]

I also have this problem on .NET MAUI, it always happens on windows on a specific page. I think there are some features windows doesn't support and weren't noticed by Microsoft when released.

[holecekp]

I am experiencing this crash in .NET MAUI. The previous Xamarin.Forms version (which used UWP) worked fine. The MAUI version crashes with error "Layout cycle detected. Layout could not complete.". The crashing page contains a lazily-loaded view that has FlexLayout with a few items.

[github-actions[bot]]

This issue is stale because it has been open 180 days with no activity. Remove stale label or comment or this will be closed in 5 days.

[jamesk-ctx]

This issue happens consistently on Windows when moving a window between monitors with different Text Scales (one monitor is 100%, the other 150%). In my case it was caused by a Grid nested inside a Frame (although the actual issue may have been triggered by having too many height/width fields set to Auto or *; it's difficult to know). A simple layout that generates the issue is:

<ContentView ... >
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>
        <Frame Grid.Row="0" CornerRadius="4">  <!-- Removing the wrapping frame resolves the "cycle" -->
            <Grid>
                 <!-- some controls .... -->
                 ...

[Abe-Froman]

Strangely I started hitting this tonight.

Worked from the office today, everything was fine right up through my final commit/push. I came home, pulled, and hit this running under VS. My exception details look the same as OP's, except every now and the (1 out of 10) my exception message is instead "No such interface supported".

I'm on a WinUI 3 app using CommunityToolkit template and packages. Aside from that I can't really give much more info aside from a "me too". It's unsettling to get a null stack trace.

[codendone]

The original repro descriptions in this issue should be fixed by a core layout change which was just completed for 1.5. Any layout issues which repro with the fix should be logged as new issues with specific repros to investigate.