Thanks for the provided sample.
I have investigated sample and noticed few things. Firstly, the TreeList is bound to the first item of the dataSource - not to the dataSource itself.
You should create a model which has a property that references the dataSource and bind the view to that model.
Furthermore, the sync method syncs the current state of the data within the dataSource to the data provider. It is necessary to specify the transport configuration
Below you will find a modified version of the provided sample:
Get quickly onboarded and successful
with your Telerik and/or Kendo UI products with the Virtual Classroom free technical training, available to all active customers. Learn More.