AutoCAD Architecture :: How To Rename Some Nodes In Classification Tree

I need to rename some nodes in a classification tree but I keep on getting the exception.message "eInvalidInput" from the exception.source Acdbmgd.

Here is the

<Autodesk.AutoCAD.Runtime.
CommandMethod("RenameClassificationTreeNode")> _
PublicSub RenameClassificationTreeNode()
Dim ed AsEditor = Application.DocumentManager.MdiActiveDocument.Editor()
Dim db AsDatabase = HostApplicationServices.WorkingDatabase

[Code]...

'Here is the task: Remove paranthesis if present

IfNot (node.Id.IsNull) Then
Dim Clsfc AsClassification = CType(tr.GetObject(node.Id, OpenMode.ForRead), Classification)
Dim OldName AsString = Clsfc.Name
If OldName.Contains("(") AndAlso OldName.Contains(")") Then

[Code]....