Warning while disconnecting pool - not sure what it means...

[Hx Jai]

Does anyone know what this means.... (tank is the name of the pool)

Code:

   
"These running processes are using tank"
    - python3.8
    - python3.8

Full screenshot of message...

I'm also getting this error in an alert every couple hours...

Code:

The following alert has been cleared:
* Failed to check for alert VolumeStatus:
Traceback (most recent call last):
File "/usr/local/lib/python3.8/site-packages/middlewared/plugins/alert.py", line 706, in __run_source
alerts = (await alert_source.check()) or []
File "/usr/local/lib/python3.8/site-packages/middlewared/alert/source/volume_status.py", line 31, in check
for vdev in await self.middleware.call("pool.flatten_topology", pool["topology"]):
File "/usr/local/lib/python3.8/site-packages/middlewared/main.py", line 1233, in call
return await self._call(
File "/usr/local/lib/python3.8/site-packages/middlewared/main.py", line 1202, in _call
return await self.run_in_executor(prepared_call.executor, methodobj, *prepared_call.args)
File "/usr/local/lib/python3.8/site-packages/middlewared/main.py", line 1106, in run_in_executor
return await loop.run_in_executor(pool, functools.partial(method, *args, **kwargs))
File "/usr/local/lib/python3.8/site-packages/middlewared/utils/io_thread_pool_executor.py", line 25, in run
result = self.fn(*self.args, **self.kwargs)
File "/usr/local/lib/python3.8/site-packages/middlewared/plugins/pool.py", line 431, in flatten_topology
d = deque(sum(topology.values(), []))
AttributeError: 'NoneType' object has no attribute 'values'