Swimbot Error

Traceback (most recent call last):
  File "/home/pi/.local/lib/python3.7/site-packages/discord/iterators.py", line 263, in next
    return self.messages.get_nowait()
  File "/usr/lib/python3.7/asyncio/queues.py", line 182, in get_nowait
    raise QueueEmpty
asyncio.queues.QueueEmpty

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/pi/.local/lib/python3.7/site-packages/discord/channel.py", line 379, in purge
    msg = await iterator.next()
  File "/home/pi/.local/lib/python3.7/site-packages/discord/iterators.py", line 265, in next
    raise NoMoreItems()
discord.errors.NoMoreItems

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/pi/.local/lib/python3.7/site-packages/discord/ext/commands/core.py", line 85, in wrapped
    ret = await coro(*args, **kwargs)
  File "/home/pi/Swimbot/server_manager.py", line 61, in purge
    deleted = await ctx.channel.purge(limit=number)
  File "/home/pi/.local/lib/python3.7/site-packages/discord/channel.py", line 388, in purge
    await ret[-1].delete()
  File "/home/pi/.local/lib/python3.7/site-packages/discord/message.py", line 801, in delete
    await self._state.http.delete_message(self.channel.id, self.id)
  File "/home/pi/.local/lib/python3.7/site-packages/discord/http.py", line 243, in request
    raise NotFound(r, data)
discord.errors.NotFound: 404 Not Found (error code: 10008): Unknown Message