/dcim/cables/: 'NoneType' object has no attribute '_base_manager'

[herbetom]

I'm seeing the following Error when i try to access /dcim/cables/ with DEBUG=true:

From what i've seen this could be something like #8425. Hoewer that specific error seems to have gotten fixed.

I'm currently running Netbox Version v3.1.8 in a docker setup.

Any ideas are appreciated.

Environment:


Request Method: GET
Request URL: https://netbox.darmstadt.freifunk.net/dcim/cables/

Django Version: 3.2.12
Python Version: 3.9.5
Installed Applications:
['django.contrib.admin',
 'django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'django.contrib.humanize',
 'corsheaders',
 'debug_toolbar',
 'graphiql_debug_toolbar',
 'django_filters',
 'django_tables2',
 'django_prometheus',
 'graphene_django',
 'mptt',
 'rest_framework',
 'social_django',
 'taggit',
 'timezone_field',
 'circuits',
 'dcim',
 'ipam',
 'extras',
 'tenancy',
 'users',
 'utilities',
 'virtualization',
 'wireless',
 'django_rq',
 'drf_yasg']
Installed Middleware:
['graphiql_debug_toolbar.middleware.DebugToolbarMiddleware',
 'django_prometheus.middleware.PrometheusBeforeMiddleware',
 'corsheaders.middleware.CorsMiddleware',
 'django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.common.CommonMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware',
 'django.middleware.clickjacking.XFrameOptionsMiddleware',
 'django.middleware.security.SecurityMiddleware',
 'netbox.middleware.ExceptionHandlingMiddleware',
 'netbox.middleware.RemoteUserMiddleware',
 'netbox.middleware.LoginRequiredMiddleware',
 'netbox.middleware.DynamicConfigMiddleware',
 'netbox.middleware.APIVersionMiddleware',
 'netbox.middleware.ObjectChangeMiddleware',
 'django_prometheus.middleware.PrometheusAfterMiddleware']


Template error:
In template /opt/netbox/netbox/templates/inc/table_htmx.html, error at line 25
   'NoneType' object has no attribute '_base_manager'
   15 :                 >{{ column.header }}</a>
   16 :               </th>
   17 :             {% else %}
   18 :               <th {{ column.attrs.th.as_html }}>{{ column.header }}</th>
   19 :             {% endif %}
   20 :           {% endfor %}
   21 :         </tr>
   22 :       </thead>
   23 :     {% endif %}
   24 :     <tbody>
   25 :        {% for row in table.page.object_list|default:table.rows %} 
   26 :         <tr {{ row.attrs.as_html }}>
   27 :           {% for column, cell in row.items %}
   28 :             <td {{ column.attrs.td.as_html }}>{{ cell }}</td>
   29 :           {% endfor %}
   30 :         </tr>
   31 :       {% empty %}
   32 :         {% if table.empty_text %}
   33 :           <tr>
   34 :             <td colspan="{{ table.columns|length }}" class="text-center text-muted">&mdash; {{ table.empty_text }} &mdash;</td>
   35 :           </tr>


Traceback (most recent call last):
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/core/handlers/exception.py", line 47, in inner
    response = get_response(request)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/core/handlers/base.py", line 181, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/views/generic/base.py", line 70, in view
    return self.dispatch(request, *args, **kwargs)
  File "/opt/netbox/netbox/utilities/views.py", line 93, in dispatch
    return super().dispatch(request, *args, **kwargs)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/views/generic/base.py", line 98, in dispatch
    return handler(request, *args, **kwargs)
  File "/opt/netbox/netbox/netbox/views/generic.py", line 274, in get
    return render(request, self.template_name, context)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/shortcuts.py", line 19, in render
    content = loader.render_to_string(template_name, context, request, using=using)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/template/loader.py", line 62, in render_to_string
    return template.render(context, request)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/template/backends/django.py", line 61, in render
    return self.template.render(context)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/template/base.py", line 170, in render
    return self._render(context)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/test/utils.py", line 100, in instrumented_test_render
    return self.nodelist.render(context)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/template/base.py", line 938, in render
    bit = node.render_annotated(context)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/template/base.py", line 905, in render_annotated
    return self.render(context)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/template/loader_tags.py", line 150, in render
    return compiled_parent._render(context)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/test/utils.py", line 100, in instrumented_test_render
    return self.nodelist.render(context)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/template/base.py", line 938, in render
    bit = node.render_annotated(context)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/template/base.py", line 905, in render_annotated
    return self.render(context)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/template/loader_tags.py", line 150, in render
    return compiled_parent._render(context)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/test/utils.py", line 100, in instrumented_test_render
    return self.nodelist.render(context)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/template/base.py", line 938, in render
    bit = node.render_annotated(context)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/template/base.py", line 905, in render_annotated
    return self.render(context)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/template/loader_tags.py", line 62, in render
    result = block.nodelist.render(context)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/template/base.py", line 938, in render
    bit = node.render_annotated(context)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/template/base.py", line 905, in render_annotated
    return self.render(context)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/template/loader_tags.py", line 62, in render
    result = block.nodelist.render(context)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/template/base.py", line 938, in render
    bit = node.render_annotated(context)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/template/base.py", line 905, in render_annotated
    return self.render(context)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/template/loader_tags.py", line 195, in render
    return template.render(context)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/template/base.py", line 172, in render
    return self._render(context)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/test/utils.py", line 100, in instrumented_test_render
    return self.nodelist.render(context)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/template/base.py", line 938, in render
    bit = node.render_annotated(context)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/template/base.py", line 905, in render_annotated
    return self.render(context)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django_tables2/templatetags/django_tables2.py", line 167, in render
    return template.render(context={"table": table}, request=request)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/template/backends/django.py", line 61, in render
    return self.template.render(context)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/template/base.py", line 170, in render
    return self._render(context)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/test/utils.py", line 100, in instrumented_test_render
    return self.nodelist.render(context)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/template/base.py", line 938, in render
    bit = node.render_annotated(context)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/template/base.py", line 905, in render_annotated
    return self.render(context)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/template/defaulttags.py", line 166, in render
    values = self.sequence.resolve(context, ignore_failures=True)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/template/base.py", line 698, in resolve
    new_obj = func(obj, *arg_vals)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/template/defaultfilters.py", line 782, in default
    return value or arg
  File "/opt/netbox/venv/lib/python3.9/site-packages/django_tables2/rows.py", line 325, in __len__
    length = len(self.data)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/db/models/query.py", line 262, in __len__
    self._fetch_all()
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/db/models/query.py", line 1326, in _fetch_all
    self._prefetch_related_objects()
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/db/models/query.py", line 813, in _prefetch_related_objects
    prefetch_related_objects(self._result_cache, *self._prefetch_related_lookups)
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/db/models/query.py", line 1730, in prefetch_related_objects
    obj_list, additional_lookups = prefetch_one_level(
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/db/models/query.py", line 1855, in prefetch_one_level
    prefetcher.get_prefetch_queryset(instances, lookup.get_current_queryset(level)))
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/contrib/contenttypes/fields.py", line 195, in get_prefetch_queryset
    ret_val.extend(ct.get_all_objects_for_this_type(pk__in=fkeys))
  File "/opt/netbox/venv/lib/python3.9/site-packages/django/contrib/contenttypes/models.py", line 181, in get_all_objects_for_this_type
    return self.model_class()._base_manager.using(self._state.db).filter(**kwargs)

Exception Type: AttributeError at /dcim/cables/
Exception Value: 'NoneType' object has no attribute '_base_manager'

[candlerb]

Was your Netbox originally installed as an older version and then upgraded? If so, maybe it's related to one of these: #6745, #8166

I have seen cases where the cable model in Netbox was in an inconsistent state, and there are some database constraints missing which would have prevent this problem occurring. Nobody has gotten to the bottom of this yet AFAIK, because if you install Netbox from scratch you do get the constraints.

[herbetom]

Yes, it was upgraded multiple times. So probably it's something along those lines ... :( Thanks!