Error with Slack API

[stevegon3]

When using Python3.7 Anaconda Windows 10 on Jupyter with the Slack API you get an error. Slack has confirmed this is a problem with Jupyter and it does work when using the command line Python instead of Jupyter.
The package name is slack and it happens when doing a simple post message
client.chat_postMessage(

RuntimeError Traceback (most recent call last)
in
11 client.chat_postMessage(
12 channel="GQ0GJDNE8",
---> 13 text="Hello from your app! 🎉"
14 )

C:\ProgramData\Anaconda3\lib\site-packages\slack\web\client.py in chat_postMessage(self, channel, **kwargs)
380 """
381 kwargs.update({"channel": channel})
--> 382 return self.api_call("chat.postMessage", json=kwargs)
383
384 def chat_scheduleMessage(

C:\ProgramData\Anaconda3\lib\site-packages\slack\web\base_client.py in api_call(self, api_method, http_verb, files, data, params, json, headers, auth)
170 return future
171
--> 172 return self._event_loop.run_until_complete(future)
173
174 def _validate_xoxp_token(self):

C:\ProgramData\Anaconda3\lib\asyncio\base_events.py in run_until_complete(self, future)
569 future.add_done_callback(_run_until_complete_cb)
570 try:
--> 571 self.run_forever()
572 except:
573 if new_task and future.done() and not future.cancelled():

C:\ProgramData\Anaconda3\lib\asyncio\base_events.py in run_forever(self)
524 self._check_closed()
525 if self.is_running():
--> 526 raise RuntimeError('This event loop is already running')
527 if events._get_running_loop() is not None:
528 raise RuntimeError(

RuntimeError: This event loop is already running