Re: Treeview, delete the selected row (can't get it done :( )
The error message means, that the passed iterator is not valid for your listStore.
You can check this yourself with
listStore.IterIsValid(iterSelected);
It will return true if the iter is valid, false otherwise.
WHY it is not valid I can't see with the code you showd.
Can you show the line where you connect the OnSelectionChanged Method with the Changed Event?