Failed to check for alert Quota - traceback

Freenas generates the following alert (also sent via email):

[code]

New alert:
* Failed to check for alert Quota:
Traceback (most recent call last):
  File "/usr/local/lib/python3.7/site-packages/middlewared/plugins/alert.py", line 660, in __run_source
    alerts = (await alert_source.check()) or []
  File "/usr/local/lib/python3.7/site-packages/middlewared/alert/base.py", line 204, in check
    return await self.middleware.run_in_thread(self.check_sync)
  File "/usr/local/lib/python3.7/site-packages/middlewared/utils/run_in_thread.py", line 10, in run_in_thread
    return await self.loop.run_in_executor(self.run_in_thread_executor, functools.partial(method, *args, **kwargs))
  File "/usr/local/lib/python3.7/site-packages/middlewared/utils/io_thread_pool_executor.py", line 25, in run
    result = self.fn(*self.args, **self.kwargs)
  File "/usr/local/lib/python3.7/site-packages/middlewared/plugins/../alert/source/quota.py", line 90, in check_sync
    owner = self._get_owner(dataset)
  File "/usr/local/lib/python3.7/site-packages/middlewared/plugins/../alert/source/quota.py", line 131, in _get_owner
    logger.debug("Unable to get mountpoint for dataset %r, assuming owner = root", dataset["name"]["value"])
TypeError: string indices must be integers

[/code]

Let me know if you need more information.