What does this mean?
How do I fix it?
KeyError: Equity(11280, symbol=u'CUBA', asset_name=u'HERZFELD CARIBBEAN BASIN FUND', exchange=u'NASDAQ GLOBAL MARKET', start_date=Timestamp('1994-05-20 00:00:00+0000', tz='UTC'), end_date=Timestamp('2016-02-23 00:00:00+0000', tz='UTC'), first_traded=None, auto_close_date=None)