Failed to umount dataset: cannot unmount '/mnt/.ix-apps'

Hello i have tried to unset the pool under Applications/configuration/unset Pool

i get this error

how can i unset the application pool?

all installed apps were stopped and then deleted from the webui

TrueNas ElectricEel-24.10.0.2

concurrent.futures.process._RemoteTraceback: 
"""
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/middlewared/plugins/zfs_/dataset_actions.py", line 77, in umount
    with libzfs.ZFS() as zfs:
  File "libzfs.pyx", line 534, in libzfs.ZFS.__exit__
  File "/usr/lib/python3/dist-packages/middlewared/plugins/zfs_/dataset_actions.py", line 79, in umount
    dataset.umount(force=options['force'])
  File "libzfs.pyx", line 4287, in libzfs.ZFSDataset.umount
libzfs.ZFSException: cannot unmount '/mnt/.ix-apps': pool or dataset is busy

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3.11/concurrent/futures/process.py", line 256, in _process_worker
    r = call_item.fn(*call_item.args, **call_item.kwargs)
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/middlewared/worker.py", line 112, in main_worker
    res = MIDDLEWARE._run(*call_args)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/middlewared/worker.py", line 46, in _run
    return self._call(name, serviceobj, methodobj, args, job=job)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/middlewared/worker.py", line 34, in _call
    with Client(f'ws+unix://{MIDDLEWARE_RUN_DIR}/middlewared-internal.sock', py_exceptions=True) as c:
  File "/usr/lib/python3/dist-packages/middlewared/worker.py", line 40, in _call
    return methodobj(*params)
           ^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/middlewared/schema/processor.py", line 183, in nf
    return func(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/middlewared/plugins/zfs_/dataset_actions.py", line 82, in umount
    raise CallError(f'Failed to umount dataset: {e}')
middlewared.service_exception.CallError: [EFAULT] Failed to umount dataset: cannot unmount '/mnt/.ix-apps': pool or dataset is busy
"""

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/middlewared/plugins/docker/update.py", line 90, in do_update
    await self.middleware.call('service.stop', 'docker')
  File "/usr/lib/python3/dist-packages/middlewared/main.py", line 1626, in call
    return await self._call(
           ^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/middlewared/main.py", line 1457, in _call
    return await methodobj(*prepared_call.args)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/middlewared/schema/processor.py", line 179, in nf
    return await func(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/middlewared/schema/processor.py", line 49, in nf
    res = await f(*args, **kwargs)
          ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/middlewared/plugins/service.py", line 267, in stop
    await service_object.after_stop()
  File "/usr/lib/python3/dist-packages/middlewared/plugins/service_/services/docker.py", line 72, in after_stop
    await self.mount_umount_ix_apps(False)
  File "/usr/lib/python3/dist-packages/middlewared/plugins/service_/services/docker.py", line 19, in mount_umount_ix_apps
    await self.middleware.call('zfs.dataset.umount', docker_ds, {'force': True})
  File "/usr/lib/python3/dist-packages/middlewared/main.py", line 1626, in call
    return await self._call(
           ^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/middlewared/main.py", line 1465, in _call
    return await self._call_worker(name, *prepared_call.args)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/middlewared/main.py", line 1471, in _call_worker
    return await self.run_in_proc(main_worker, name, args, job)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/middlewared/main.py", line 1377, in run_in_proc
    return await self.run_in_executor(self.__procpool, method, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/middlewared/main.py", line 1361, in run_in_executor
    return await loop.run_in_executor(pool, functools.partial(method, *args, **kwargs))
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
middlewared.service_exception.CallError: [EFAULT] Failed to umount dataset: cannot unmount '/mnt/.ix-apps': pool or dataset is busy

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/middlewared/job.py", line 488, in run
    await self.future
  File "/usr/lib/python3/dist-packages/middlewared/job.py", line 533, in __run_body
    rv = await self.method(*args)
         ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/middlewared/schema/processor.py", line 49, in nf
    res = await f(*args, **kwargs)
          ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/middlewared/schema/processor.py", line 179, in nf
    return await func(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/middlewared/plugins/docker/update.py", line 92, in do_update
    raise CallError(f'Failed to stop docker service: {e}')
middlewared.service_exception.CallError: [EFAULT] Failed to stop docker service: [EFAULT] Failed to umount dataset: cannot unmount '/mnt/.ix-apps': pool or dataset is busy