When using version 2023.2.718 targeting .NET 6.0 on VS 2022, I tried to create a RadCartesianChart as described here: https://docs.telerik.com/devtools/wpf/controls/radchartview/multiple-chart-series
The PointSeries and BarSeries are recognized as expected, but LineSeries generates errors that make the designer complain about invalid markup:
The program builds and runs fine.
Anyone have a clue as to what is happening here?