# Buggy code
def send_msg(self, msg: Dict[str, Any]) -> None:
    """Send a message to telegram channel"""
    try:
        if msg["type"] == RPCMessageType.BUY_NOTIFICATION:
            valuedict = self._config["webhook"].get("webhookbuy", None)
        elif msg["type"] == RPCMessageType.SELL_NOTIFICATION:
            valuedict = self._config["webhook"].get("webhooksell", None)
        elif msg["type"] in (
            RPCMessageType.STATUS_NOTIFICATION,
            RPCMessageType.CUSTOM_NOTIFICATION,
            RPCMessageType.WARNING_NOTIFICATION,
        ):
            valuedict = self._config["webhook"].get("webhookstatus", None)
        else:
            raise NotImplementedError("Unknown message type: {}".format(msg["type"]))
        if not valuedict:
            logger.info("Message type %s not configured for webhooks", msg["type"])
            return

        payload = {key: value.format(**msg) for (key, value) in valuedict.items()}
        self._send_msg(payload)
    except KeyError as exc:
        logger.exception(
            "Problem calling Webhook. Please check your webhook configuration. "
            "Exception: %s",
            exc,
        )


# Traceback (Exception)
2020-02-20 22:47:28,025 - freqtrade - ERROR - Fatal exception!
Traceback (most recent call last):
File "/opt/tradebot/freqtrade/.env/lib/python3.7/site-packages/talib/__init__.py", line 20, in wrapper
for arg in chain(args, kwargs.values())
StopIteration

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/freqtrade/freqtrade/main.py", line 36, in main
return_code = args['func'](args)
File "/freqtrade/freqtrade/commands/optimize_commands.py", line 76, in start_hyperopt
hyperopt.start()
File "/freqtrade/freqtrade/optimize/hyperopt.py", line 488, in start
preprocessed = self.backtesting.strategy.tickerdata_to_dataframe(data)
File "/freqtrade/freqtrade/strategy/interface.py", line 448, in tickerdata_to_dataframe
for pair, pair_data in tickerdata.items()}
File "/freqtrade/freqtrade/strategy/interface.py", line 448, in <dictcomp>
for pair, pair_data in tickerdata.items()}
File "/freqtrade/freqtrade/strategy/interface.py", line 464, in advise_indicators
return self.populate_indicators(dataframe, metadata)
File "/freqtrade/user_data/strategies/MyDev.py", line 205, in populate_indicators
dataframe['mfi'] = ta.MFI(dataframe)
File "talib/_abstract.pxi", line 352, in talib._ta_lib.Function.__call__
File "talib/_abstract.pxi", line 383, in talib._ta_lib.Function.__call_function
File "/opt/tradebot/freqtrade/.env/lib/python3.7/site-packages/talib/__init__.py", line 24, in wrapper
return func(*args, **kwargs)
File "talib/_func.pxi", line 8454, in talib._ta_lib.MFI
Exception: volume is not double

# Fixed code
def send_msg(self, msg: Dict[str, Any]) -> None:
    """Send a message to telegram channel"""
    try:
        if msg["type"] == RPCMessageType.BUY_NOTIFICATION:
            valuedict = self._config["webhook"].get("webhookbuy", None)
        elif msg["type"] == RPCMessageType.BUY_CANCEL_NOTIFICATION:
            valuedict = self._config["webhook"].get("webhookbuycancel", None)
        elif msg["type"] == RPCMessageType.SELL_NOTIFICATION:
            valuedict = self._config["webhook"].get("webhooksell", None)
        elif msg["type"] == RPCMessageType.SELL_CANCEL_NOTIFICATION:
            valuedict = self._config["webhook"].get("webhooksellcancel", None)
        elif msg["type"] in (
            RPCMessageType.STATUS_NOTIFICATION,
            RPCMessageType.CUSTOM_NOTIFICATION,
            RPCMessageType.WARNING_NOTIFICATION,
        ):
            valuedict = self._config["webhook"].get("webhookstatus", None)
        else:
            raise NotImplementedError("Unknown message type: {}".format(msg["type"]))
        if not valuedict:
            logger.info("Message type %s not configured for webhooks", msg["type"])
            return

        payload = {key: value.format(**msg) for (key, value) in valuedict.items()}
        self._send_msg(payload)
    except KeyError as exc:
        logger.exception(
            "Problem calling Webhook. Please check your webhook configuration. "
            "Exception: %s",
            exc,
        )