Dear list,
on our Mailman 3 system we are hitting the following error by clicking a link to admin/django_q/ormq/:
Server Error
The Log prints:
---
ERROR 2019-08-26 08:48:01,704 10311 django.request Internal Server Error: /admin/django_q/ormq/
Traceback (most recent call last):
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/db/models/options.py", line 566, in get_field
    return self.fields_map[field_name]
KeyError: 'task_id'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/contrib/admin/utils.py", line 276, in lookup_field
    f = _get_non_gfk_field(opts, name)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/contrib/admin/utils.py", line 307, in _get_non_gfk_field
    field = opts.get_field(name)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/db/models/options.py", line 568, in get_field
    raise FieldDoesNotExist("%s has no field named '%s'" % (self.object_name, field_name))
django.core.exceptions.FieldDoesNotExist: OrmQ has no field named 'task_id'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/core/handlers/exception.py", line 35, in inner
    response = get_response(request)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/core/handlers/base.py", line 158, in _get_response
    response = self.process_exception_by_middleware(e, request)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/core/handlers/base.py", line 156, in _get_response
    response = response.render()
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/response.py", line 106, in render
    self.content = self.rendered_content
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/response.py", line 83, in rendered_content
    content = template.render(context, self._request)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/backends/django.py", line 61, in render
    return self.template.render(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/base.py", line 175, in render
    return self._render(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/base.py", line 167, in _render
    return self.nodelist.render(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/base.py", line 943, in render
    bit = node.render_annotated(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/base.py", line 910, in render_annotated
    return self.render(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/loader_tags.py", line 155, in render
    return compiled_parent._render(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/base.py", line 167, in _render
    return self.nodelist.render(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/base.py", line 943, in render
    bit = node.render_annotated(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/base.py", line 910, in render_annotated
    return self.render(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/loader_tags.py", line 155, in render
    return compiled_parent._render(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/base.py", line 167, in _render
    return self.nodelist.render(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/base.py", line 943, in render
    bit = node.render_annotated(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/base.py", line 910, in render_annotated
    return self.render(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/loader_tags.py", line 67, in render
    result = block.nodelist.render(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/base.py", line 943, in render
    bit = node.render_annotated(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/base.py", line 910, in render_annotated
    return self.render(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/loader_tags.py", line 67, in render
    result = block.nodelist.render(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/base.py", line 943, in render
    bit = node.render_annotated(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/base.py", line 910, in render_annotated
    return self.render(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/library.py", line 214, in render
    _dict = self.func(*resolved_args, **resolved_kwargs)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/contrib/admin/templatetags/admin_list.py", line 326, in result_list
    'results': list(results(cl))}
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/contrib/admin/templatetags/admin_list.py", line 302, in results
    yield ResultList(None, items_for_result(cl, res, None))
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/contrib/admin/templatetags/admin_list.py", line 293, in __init__
    super().__init__(*items)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/contrib/admin/templatetags/admin_list.py", line 212, in items_for_result
    f, attr, value = lookup_field(field_name, result, cl.model_admin)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/contrib/admin/utils.py", line 289, in lookup_field
    value = attr()
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django_q/models.py", line 200, in task_id
    return self.task()['id']
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django_q/models.py", line 194, in task
    return SignedPackage.loads(self.payload)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django_q/signing.py", line 31, in loads
    serializer=PickleSerializer)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django_q/core_signing.py", line 38, in loads
    return serializer().loads(data)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django_q/signing.py", line 44, in loads
    return pickle.loads(data)
UnicodeDecodeError: 'ascii' codec can't decode byte 0xe2 in position 1: ordinal not in range(128)
ERROR 2019-08-26 08:48:01,704 10311 django.request Internal Server Error: /admin/django_q/ormq/
Traceback (most recent call last):
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/db/models/options.py", line 566, in get_field
    return self.fields_map[field_name]
KeyError: 'task_id'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/contrib/admin/utils.py", line 276, in lookup_field
    f = _get_non_gfk_field(opts, name)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/contrib/admin/utils.py", line 307, in _get_non_gfk_field
    field = opts.get_field(name)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/db/models/options.py", line 568, in get_field
    raise FieldDoesNotExist("%s has no field named '%s'" % (self.object_name, field_name))
django.core.exceptions.FieldDoesNotExist: OrmQ has no field named 'task_id'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/core/handlers/exception.py", line 35, in inner
    response = get_response(request)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/core/handlers/base.py", line 158, in _get_response
    response = self.process_exception_by_middleware(e, request)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/core/handlers/base.py", line 156, in _get_response
    response = response.render()
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/response.py", line 106, in render
    self.content = self.rendered_content
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/response.py", line 83, in rendered_content
    content = template.render(context, self._request)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/backends/django.py", line 61, in render
    return self.template.render(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/base.py", line 175, in render
    return self._render(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/base.py", line 167, in _render
    return self.nodelist.render(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/base.py", line 943, in render
    bit = node.render_annotated(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/base.py", line 910, in render_annotated
    return self.render(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/loader_tags.py", line 155, in render
    return compiled_parent._render(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/base.py", line 167, in _render
    return self.nodelist.render(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/base.py", line 943, in render
    bit = node.render_annotated(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/base.py", line 910, in render_annotated
    return self.render(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/loader_tags.py", line 155, in render
    return compiled_parent._render(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/base.py", line 167, in _render
    return self.nodelist.render(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/base.py", line 943, in render
    bit = node.render_annotated(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/base.py", line 910, in render_annotated
    return self.render(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/loader_tags.py", line 67, in render
    result = block.nodelist.render(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/base.py", line 943, in render
    bit = node.render_annotated(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/base.py", line 910, in render_annotated
    return self.render(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/loader_tags.py", line 67, in render
    result = block.nodelist.render(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/base.py", line 943, in render
    bit = node.render_annotated(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/base.py", line 910, in render_annotated
    return self.render(context)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/template/library.py", line 214, in render
    _dict = self.func(*resolved_args, **resolved_kwargs)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/contrib/admin/templatetags/admin_list.py", line 326, in result_list
    'results': list(results(cl))}
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/contrib/admin/templatetags/admin_list.py", line 302, in results
    yield ResultList(None, items_for_result(cl, res, None))
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/contrib/admin/templatetags/admin_list.py", line 293, in __init__
    super().__init__(*items)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/contrib/admin/templatetags/admin_list.py", line 212, in items_for_result
    f, attr, value = lookup_field(field_name, result, cl.model_admin)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django/contrib/admin/utils.py", line 289, in lookup_field
    value = attr()
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django_q/models.py", line 200, in task_id
    return self.task()['id']
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django_q/models.py", line 194, in task
    return SignedPackage.loads(self.payload)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django_q/signing.py", line 31, in loads
    serializer=PickleSerializer)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django_q/core_signing.py", line 38, in loads
    return serializer().loads(data)
  File "/opt/mailman/mailman-venv/lib/python3.6/site-packages/django_q/signing.py", line 44, in loads
    return pickle.loads(data)
UnicodeDecodeError: 'ascii' codec can't decode byte 0xe2 in position 1: ordinal not in range(128)
---
Any ideas how to see the complete queue an maybe delete some defunct entries?