Ticker AAPL
From 2020-05-06 00:00:00
Security Type Equity
Market USA
Resolution Daily
Status Resolved

Runtime Error: In Scheduled Event 'AAPL: EveryDay: AAPL: 0 min after MarketOpen', 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 UTX R735QTJ8XC9X key exist in the collection and/or that collection is not empty.
at Rebalance in main.py:line 83 :: symbols = self.SelectSymbols(history)
at SelectSymbols in main.py:line 110 :: returns = history[symbol].pct_change().dropna()
KeyError : 'UTX R735QTJ8XC9X'

Algorithm was handling AAPL fine for the prior 4 years backtested.