Adding New Lines to the DataGrid Fails in AddItems Method of the TwoListSync Class.

[BtrentIT]

Hi Chris,

I tried using your code and it all worked fine until I tried adding a new row to the Data Grid.
'The value "{NewItemPlaceholder}" is not of type "WpfMvvmDataGridMultiselect.Person" and cannot be used in this generic collection.
Parameter name: value'
Screenshot as per below.

As I am not very experienced with C# yet I am not sure what is going on with it for this to happen but thought I would paste this up here in case someone ends up figuring it out.

Regards
Ben