Is there a trick to get this module to work? I just get inconsistent error after error. Most common are when the page loads, An error has occurred.
Error: Category is currently unavailable. in the categories module and this one in the event log:

Message: DotNetNuke.Services.Exceptions.ModuleLoadException: Value cannot be null. Parameter name: key ---> System.ArgumentNullException: Value cannot be null. Parameter name: key at System.ThrowHelper.ThrowArgumentNullException(ExceptionArgument argument) at System.Collections.Generic.SortedList`2.IndexOfKey(TKey key) at System.Collections.Generic.SortedList`2.ContainsKey(TKey key) at r2i.OWS.Wrapper.DNN.Dnn.OnModuleCommunication(Object s, ModuleCommunicationEventArgs e) at DotNetNuke.Entities.Modules.Communications.ModuleCommunicationEventHandler.Invoke(Object sender, ModuleCommunicationEventArgs e) at DotNetNuke.Modules.Help.NavPane.SelectNode() at DotNetNuke.Modules.Help.NavPane.Page_Load(Object sender, EventArgs e) --- End of inner exception stack trace ---