Usually this kind of exception appears when you try to use both ItemsSource
properties of an ItemsControl
. You can make a simple test. Use a ListBox
, add ListBoxItem
to its Items collection and then set the ItemsSource
property to some collection of objects. This will lead to the same exception.
So could you please make sure that by the time ItemsSource of the RadTreeView is being set , the Items collection is empty ?
Please let us know if this helps you proceed further.
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