Stack trace:

Type: KeyNotFoundException

Message: Arg_KeyNotFound
   at Telerik.Data.Core.Layouts.StaggeredRenderInfo.PhysicalOffsetFromSlot(Int32 slot)
   at Telerik.Data.Core.Layouts.StaggeredLayout.PhysicalOffsetFromSlot(Int32 slot)
   at Telerik.UI.Xaml.Controls.Data.ListViewModel.ScrollIndexIntoView(UI.Xaml.Controls.Primitives.ScrollIntoViewOperation<System.Nullable<Telerik.Data.Core.Layouts.ItemInfo>> operation)
   at Telerik.UI.Xaml.Controls.Data.ListViewModel.<>c__DisplayClass55_0.<ScrollIndexIntoViewCore>b__0()
   at System.Action.Invoke()
   at Telerik.UI.Xaml.Controls.Primitives.DelegateUpdate<Telerik.UI.Xaml.Controls.Grid.UpdateFlags>.Process()
   at Telerik.UI.Xaml.Controls.Primitives.UpdateServiceBase<Telerik.UI.Xaml.Controls.Data.ListView.UpdateFlags>.ProcessUpdatesQueue()
   at Telerik.UI.Xaml.Controls.Primitives.UpdateServiceBase<Telerik.UI.Xaml.Controls.Data.ListView.UpdateFlags>.DispatchUpdates()
   at Telerik.UI.Xaml.Controls.Primitives.UpdateServiceBase<Telerik.UI.Xaml.Controls.Data.ListView.UpdateFlags>.OnUpdateCallback()

Version of Telerik.UI.for.UniversalWindowsPlatform 1.0.0.3

In some specific scenarios, scrolling the RadDataGrid results in IndexOutOfRangeException

Exception = {System.IndexOutOfRangeException: Index was outside the bounds of the array.
   at Telerik.UI.Xaml.Controls.Grid.IndexStorage.ValueForIndex(Int32 index, Boolean approximate)
   at Telerik.Data.Core.Layouts.CompactLayout.UpdateAverageLength(Int32 startInde...

TelerikChartAxisBorderBrush is not applied when setting in Dark Light ThemeResources from the Telerik Theme Resources https://docs.telerik.com/devtools/universal-windows-platform/common/teleriknamedbrushes 

Inconsistency in Line and Spline series performance

Resizing the window containing a CartesianChart with SplineSeries leads to some incorrect rendering between points:

When the SelectionMode is set to Extended and we try to select items that are not currently visible using Shift + press only the Rows that are currently visible are selected.

See this Screencast for a short video of the issue at runtime: https://www.screencast.com/t/YXm6xOtO 

Here's the code to reproduce: 

<grid:RadDataGrid ItemsSource="{x:Bind ViewModel.DataItems, Mode=OneWay}"
                  UserGroupMode="Disabled"
                  UserFilterMode="Disabled"
                  UserColumnReorderMode="None"
                  UserSortMode="None"
                  AutoGenerateColumns="False"
                  GridLinesVisibility="Horizontal">
    <grid:RadDataGrid.Columns>
        <grid:DataGridNumericalColumn Header="1"
                                      PropertyName="Key"
                                      SizeMode="Auto" />
        <grid:DataGridTextColumn Header="2"
                                 PropertyName="First"
                                 SizeMode="Auto" />
        <grid:DataGridTextColumn Header="3"
                                 PropertyName="Second"
                                 SizeMode="Auto" />
        <grid:DataGridTextColumn Header="Stretchy"
                                 PropertyName="Stretch"
                                 SizeMode="Auto" />
        <grid:DataGridTextColumn Header="5"
                                 PropertyName="SecondLast"
                                 SizeMode="Auto" />
        <grid:DataGridTextColumn Header="6"
                                 PropertyName="Last"
                                 SizeMode="Auto" />
        <grid:DataGridNumericalColumn Header="7"
                                      PropertyName="Count"
                                      SizeMode="Auto" />
    </grid:RadDataGrid.Columns>
</grid:RadDataGrid>

In a scenario where you have lots of columns so that a horizontal scrollbar is present and you try to resize columns which are not visible at the beginning(need to scroll to view them) ->  the resizing is not working as expected and the view is jumping. 

If we have a Chart with DateTimeContinuousAxis as horizontal axis, updating its Minimum and Maximum values should update the rendered in the Chart plot area data. However, if for some period (Minimum and Maximum range) there is no data, the current displayed data is not cleared.

If you populate the Chart with data through a SeriesDescriptor as explained here: How to Generate a Dynamic Series Using a Collection of Collections, the PointTemplate/PointTemplateSelector is not applied.

updating data in real-time causes flickering when series are added through the series provider

Workaround: 
Add series to the chart without using the SeriesProvider option.

When the DataGrid is placed inside a Panel (for example Grid) and after that is removed from that panel and is placed in another one the selection stops working. The issue is caused by the inaccurate order of the thrown Unloaded and Loaded events which the control relies on.

When you have several series(ScatterLineSeries reported but it happens with others as well) in the RadCartesianChart and you clear the Items of one of them by calling the Clear() method - the line is not redrawn and it shows the old data. 

When using shp and dbf files with ~130MB size, it takes minutes to load the map

The uwp radlistview vertical scrollbar disappears when focus is lost -
I think I need something like 
https://www.telerik.com/forums/listview-width-with-or-without-vertical-scrollbar
 <telerik:RadListView.Commands. ListElement.Scroller.Scrollbar.FillElement.Visibility

But I may be missing something?