Using the code below, you will find the following exception is thrown:
Happens on Android and Windows (have not tested on iOS/MacCatalyst) using UI for MAUI 0.6.0 running on MAUI preview14
Repro Code
<?xml version="1.0" encoding="utf-8" ?>
<ContentPage ... xmlns:telerikPrimitives="clr-namespace:Telerik.XamarinForms.Primitives;assembly=Telerik.Maui.Controls.Compatibility"
xmlns:telerikCommon="clr-namespace:Telerik.XamarinForms.Common;assembly=Telerik.Maui.Controls.Compatibility">
<Grid>
<Grid WidthRequest="200"
HeightRequest="200">
<telerikPrimitives:RadPath x:Name="simpleLinePath"
StrokeThickness="4"
Stroke="#2EC262">
<telerikCommon:RadPathGeometry>
<telerikCommon:RadPathFigure StartPoint="0.8, 0.1">
<telerikCommon:RadLineSegment Point="0.1, 0.8" />
</telerikCommon:RadPathFigure>
</telerikCommon:RadPathGeometry>
</telerikPrimitives:RadPath>
</Grid>
</Grid>
</ContentPage>