I am getting this exception

A first chance exception of type
'System.ComponentModel.Design.Serialization.CodeDomSerializerException'
occurred in system.design.dll

Additional information: The variable 'treeView1' is either undeclared or was
never assigned.

I am trying to call Deserialize on
((System.ComponentModel.Design.Serialization.RootCodeDomSerializer)(rootSeri
alizer)) and that fails with internal exceptions on some of components (tree
view and group box) which I placed on Panel.
I am trying to design class derived from Panel.

When I look at text of class, vars are initialized with new and added to
Controls of Panel. Do I miss something?

Rgds
Alex