Middleware error when updating

Hello. When I try to update my system I get a middleware error with the following message:

Environment:

Software Version: FreeNAS-11.1-RELEASE (dc7d195f4)
Request Method: POST
Request URL: http://192.168.1.121/system/update/apply/?uuid=a725370c1c094b4d8d9f2901551f5180

Traceback:
File "/usr/local/lib/python3.6/site-packages/django/core/handlers/exception.py" in inner
42. response = get_response(request)
File "/usr/local/lib/python3.6/site-packages/django/core/handlers/base.py" in _legacy_get_response
249. response = self._get_response(request)
File "/usr/local/lib/python3.6/site-packages/django/core/handlers/base.py" in _get_response
178. response = middleware_method(request, callback, callback_args, callback_kwargs)
File "./freenasUI/freeadmin/middleware.py" in process_view
162. return login_required(view_func)(request, *view_args, **view_kwargs)
File "/usr/local/lib/python3.6/site-packages/django/contrib/auth/decorators.py" in _wrapped_view
23. return view_func(request, *args, **kwargs)
File "./freenasUI/system/views.py" in update_apply
1269. raise MiddlewareError(handler.error)

Exception Type: MiddlewareError at /system/update/apply/
Exception Value: [MiddlewareError: Unable to remove contents for package docs]