I kept getting this error: Runtime Error: Object reference not set to an instance of an object.

So I deleted all the code that didn't give me that error until I only had this left:

class FatSkyBlueDog(QCAlgorithm):



    def Initialize(self):

        self.SetStartDate(2021, 4, 19)

        self.SetEndDate(2021, 6, 19)

        self.SetCash(100000)

        self.AddEquity("SPY")

        

        self.CustomUniverse = Universe(self)

        self.UniverseSettings.Resolution = Resolution.Daily

        self.AddUniverse(self.CustomUniverse.SelectCoarse)

        self.AddAlpha(Alpha())



    def OnData(self, data):

        pass



class Universe():

    def __init__(self, algorithm):

        self.algorithm = algorithm

    

    def SelectCoarse(self, coarse):

        symbol = self.algorithm.Symbol("SPY")

        return [symbol]

        

class Alpha():

    def __init__(self):

        pass



    def Update(self, algorithm, data):

        pass

                        

    def OnSecuritiesChanged(self, algorithm, changes):

        pass

Without the alpha model or the universe model there are no errors. It only breaks when both are there. I don't know what I did. If anyone can tell me how to fix this it would be greatly appreciated.