addextensionnode handler does not work

[Krisztian Gyuris]

In PluginManager.Initialize the AddNodeExtension calls are throwing a null reference exception. Most probably this is a Mono.Addins problem. The following lines are problematic.

AddinManager.AddExtensionNodeHandler ("/Do/ItemSource", OnIObjectChange);
AddinManager.AddExtensionNodeHandler ("/Do/Action", OnIObjectChange);