When using a CartesianGridLineAnnotation, if Value is not set, it causes an app crash. This does not happen on Android or Windows.
Code that crashes iOS app:
<telerik:RadCartesianChart x:Name="chart"
Grid.Row="0">
<telerik:RadCartesianChart.HorizontalAxis>
<telerik:NumericalAxis x:Name="xAxis" />
</telerik:RadCartesianChart.HorizontalAxis>
<telerik:RadCartesianChart.VerticalAxis>
<telerik:NumericalAxis x:Name="yAxis" />
</telerik:RadCartesianChart.VerticalAxis>
<telerik:RadCartesianChart.Series />
<telerik:RadCartesianChart.Annotations>
<telerik:CartesianGridLineAnnotation x:Name="marker"
Axis="{x:Reference xAxis}"/>
</telerik:RadCartesianChart.Annotations>
<telerik:RadCartesianChart.ChartBehaviors>
<telerik:ChartSelectionBehavior x:Name="selection"
DataPointSelectionMode="Single"
SelectionChanged="ChartSelectionBehavior_SelectionChanged" />
</telerik:RadCartesianChart.ChartBehaviors>
</telerik:RadCartesianChart>
Work around, set Value to 0
<telerik:RadCartesianChart x:Name="chart"
Grid.Row="0">
<telerik:RadCartesianChart.HorizontalAxis>
<telerik:NumericalAxis x:Name="xAxis" />
</telerik:RadCartesianChart.HorizontalAxis>
<telerik:RadCartesianChart.VerticalAxis>
<telerik:NumericalAxis x:Name="yAxis" />
</telerik:RadCartesianChart.VerticalAxis>
<telerik:RadCartesianChart.Series />
<telerik:RadCartesianChart.Annotations>
<telerik:CartesianGridLineAnnotation x:Name="marker"
Axis="{x:Reference xAxis}"
Value="0"/>
</telerik:RadCartesianChart.Annotations>
<telerik:RadCartesianChart.ChartBehaviors>
<telerik:ChartSelectionBehavior x:Name="selection"
DataPointSelectionMode="Single"
SelectionChanged="ChartSelectionBehavior_SelectionChanged" />
</telerik:RadCartesianChart.ChartBehaviors>
</telerik:RadCartesianChart>
After logging the bug report, I have also updated your account's Telerik Points as a small token of appreciation for bringing this to our attention. Thanks again!