Workspace-with-charts-won-t-save

I see other people able to save their workspace when a chart is present:
https://www.wealth-lab.com/Discussion/Workspace-charts-don-39-t-Restore-as-Saved-6787
but I am unable to do this as I get the following exception:

System.ArgumentOutOfRangeException: Specified argument was out of the range of valid values. (Parameter 'Index is out of collection's boundary.')
at System.Windows.Controls.RowDefinitionCollection.get_Item(Int32 index)
at ProccesorModel.SetupMapper(Object , Int32 , ProccesorModel )
at WealthLab.ChartWPF.Chart.get_WorkspaceString()
at QueueIdentifier.ReflectService(Object , QueueIdentifier )
at WealthLab7.cwChart.get_WorkspaceString()
at ServiceAnnotation.ReflectService(Object , ServiceAnnotation )
at WealthLab7.WorkspaceManager.InstantiateToken(MainWindow spec, Tokenizer visitor)
at WealthLab7.WorkspaceManager.CalculateToken(String config, Boolean isb)
at WealthLab7.WorkspaceManager.SaveNewWorkspace()
at WealthLab7.MainWindow.MovePage(Object )
at WealthLab7.MainWindow.EnableField(Object res, RoutedEventArgs second)
at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
at System.Windows.Controls.MenuItem.InvokeClickAfterRender(Object arg)
at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)


I can save a workspace with C# strategies for backtesting, but when a chart is present then I get this exception.

I reboot, start WL7, open a new chart (CTRL-SHFT-C), dont load any strategy or load any any indicators, but immediately try to save the workspace, and this results in the exception.

The exception says ArgumentOutOfRangeException but I can't think what this could refer to that I could be doing wrong.

I am using an i7-9850H with 16.0 GB with Windows 10 Pro 19043.1237

Perhaps I have a .Net Core issue. I have the following .NetCore SDKs
3.1.409 [C:\Program Files\dotnet\sdk]
5.0.202 [C:\Program Files\dotnet\sdk]
and with the following .NetCore runtimes
Microsoft.NETCore.App 2.1.27 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 3.1.10 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 3.1.14 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 3.1.15 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 5.0.5 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]

Please let me know what you think I could be doing wrong.
Thanks