This code has stopped working. I think symbol reference logic has changed? Can someone have a look please?
System.Collections.Generic.KeyNotFoundException: Trying to retrieve an element from a collection using a key that does not exist in that collection throws a KeyError exception. To prevent the exception, ensure that the 'VNQ', 'EEM', 'EZU', 'SPY', 'RWX', 'QQQ', 'IWM', 'IJR' key exist in the collection and/or that collection is not empty. ---> Python.Runtime.PythonException: KeyError : "None of [Index(['VNQ', 'EEM', 'EZU', 'SPY', 'RWX', 'QQQ', 'IWM', 'IJR'], dtype='object', name='symbol')] are in the [columns]"