Creating a new folder

1. Run sample at https://dojo.telerik.com/@GaloisGirl/EpuYiJOt   (cloned from https://demos.telerik.com/kendo-ui/filemanager/api , but there's no back-end error there )
2. Add new folder
3. Backend returns error (because the relative URLs throw a 404 error there)
   
4. Result:
   1. Actual: a new folder is seen in the right pane (regardless if list or grid) but not in the TreeView in the left pane
   2. Expected: state should be consistent between both panes.
      

Deleting a folder

Fails silently. The folder disappears from both views.

Renaming a folder

The renamed folder is shown as renamed in the TreeView, but the ListView or GridView hangs.

If I'm doing something wrong, an example of proper back-end error handling would be helpful.