I've been getting this for a while now, and just never posted on it until now. So its has been with multiple different version of llblgen. But im currently running v2.5. Runtime v2.0.50727
If you take a BindingSource and set say an OrderEntity as the datasource. Then create a secondary BindingSource for the OrderLineItems in the OrderEntity. So you would set the 2nd bindingsources datasource property to the first bindingsource, and set the datamember to "OrderLineItems". This should work and infact visual studio at times will automatically do this setup for you depending on what you select in the designer. However at runtime it doesnt work. I get no errors, and no data in my child grid.
I have tried with this with 2 grids (master-child) and also with combo boxes.
OrderEntity.OrderLineItems is a collection of lines items for the order.
//orders is fetched orders with order lines items prefetched.
orderBindingSource.Datasource = orders;
orderLineItemBindingSource.Datasource = orderBindingSource;
orderLineItemBindingSource.DataMember = "OrderLineItems";