System.Collections.Object.Model.ObservableCollection

I can't see what the problem is, even refactor created the same method signature but I get this error. Trying to send a collection of data to a library

System.Collections.Object.Model.ObservableCollection(Of BallGame.GameDataClass)

Cannot be converted to

System.Collections.Object.Model.ObservableCollection(Of TheCountsController.GameDataClass)

BallGame

Dim lcr = localCountsResult.returnCounts(localGameData, localDataProperties(0).drawn, localDataProperties(0).balls)

TheCountsController

PublicFunction returnCounts(CountDataAsObservableCollection(OfGameDataClass), argDrawnAsInteger, argBallsAsInteger)AsObservableCollection(OfCountsWeightClass)