MultipleObjectsReturned in PostDetailView: get() returned more than one PostContent -- it returned 2!

[MacLake]

We migrated from djangocms-blog to djangocms-stories in our multi site, multi-language project. On some, but not all detail views we get this 500 server error:

Internal Server Error: /en/conference/news/2025/01/28/save-the-date-28iphc/

MultipleObjectsReturned at /en/conference/news/2025/01/28/save-the-date-28iphc/
get() returned more than one PostContent -- it returned 2!

Request Method: GET
Request URL: https://passivehouseconference.org/en/conference/news/2025/01/28/save-the-date-28iphc/
Django Version: 5.2.9
Python Executable: /usr/bin/python3
Python Version: 3.11.2
Python Path: ['/home/py/djangocms', '/home/py/.virtualenvs/djangocms/lib/python3.11/site-packages', '/usr/lib/python311.zip', '/usr/lib/python3.11', '/usr/lib/python3.11/lib-dynload', '/home/py/.local/lib/python3.11/site-packages', '/usr/local/lib/python3.11/dist-packages', '/usr/lib/python3/dist-packages']
Server time: Fri, 05 Dec 2025 15:43:13 +0100
Installed Applications:
['dal',
 'dal_select2',
 'django_countries',
 'djangocms_admin_style',
 'django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.admin',
 'django.contrib.sites',
 'django.contrib.sitemaps',
 'djangocms_page_sitemap',
 'django.contrib.staticfiles',
 'django.contrib.messages',
 'maintenancemode',
 'cms',
 'menus',
 'sekizai',
 'treebeard',
 'djangocms_text',
 'filer',
 'easy_thumbnails',
 'djangocms_file',
 'djangocms_link',
 'djangocms_picture',
 'djangocms_photo_gallery',
 'djangocms_video',
 'djangocms_style',
 'djangocms_versioning',
 'djangocms_snippet',
 'djangocms_googlemap',
 'djangocms4_utilities',
 'reportlab',
 'djangocms_flexslider_phi',
 'djangocms_leaflet',
 'djangocms_events',
 'phi',
 'phi_plugins',
 'slam',
 'tickets',
 'conference',
 'abstracts',
 'download_files',
 'exhibitors',
 'conference_schedule',
 'djangocms_alias',
 'aldryn_boilerplates',
 'ckeditor',
 'softhyphen',
 'templated_email',
 'nested_admin',
 'aldryn_apphooks_config',
 'parler',
 'taggit',
 'taggit_autosuggest',
 'meta',
 'sortedm2m',
 'djangocms_stories',
 'django_extensions',
 'django_cleanup.apps.CleanupConfig',
 'ics',
 'django_quill',
 'djangocms_katex',
 'email_obfuscator',
 'polymorphic',
 'logentry_admin',
 'allauth',
 'allauth.account',
 'allauth.socialaccount',
 'allauth.socialaccount.providers.openid_connect',
 'djangocms_column']
Installed Middleware:
['django.middleware.security.SecurityMiddleware',
 'cms.middleware.utils.ApphookReloadMiddleware',
 'django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'maintenancemode.middleware.MaintenanceModeMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware',
 'django.middleware.locale.LocaleMiddleware',
 'django.middleware.common.CommonMiddleware',
 'django.middleware.clickjacking.XFrameOptionsMiddleware',
 'cms.middleware.user.CurrentUserMiddleware',
 'cms.middleware.page.CurrentPageMiddleware',
 'cms.middleware.toolbar.ToolbarMiddleware',
 'cms.middleware.language.LanguageCookieMiddleware',
 'allauth.account.middleware.AccountMiddleware']


Traceback (most recent call last):
  File "/home/py/.virtualenvs/djangocms/lib/python3.11/site-packages/django/core/handlers/exception.py", line 55, in inner
    response = get_response(request)
               ^^^^^^^^^^^^^^^^^^^^^
  File "/home/py/.virtualenvs/djangocms/lib/python3.11/site-packages/django/core/handlers/base.py", line 197, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/py/.virtualenvs/djangocms/lib/python3.11/site-packages/cms/utils/decorators.py", line 20, in inner
    return func(request, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/py/.virtualenvs/djangocms/lib/python3.11/site-packages/django/views/generic/base.py", line 105, in view
    return self.dispatch(request, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/py/.virtualenvs/djangocms/lib/python3.11/site-packages/djangocms_stories/views.py", line 33, in dispatch
    return super().dispatch(request, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/py/.virtualenvs/djangocms/lib/python3.11/site-packages/django/views/generic/base.py", line 144, in dispatch
    return handler(request, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/py/.virtualenvs/djangocms/lib/python3.11/site-packages/djangocms_stories/views.py", line 58, in get
    return super().get(request, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/py/.virtualenvs/djangocms/lib/python3.11/site-packages/django/views/generic/detail.py", line 112, in get
    self.object = self.get_object()
                  ^^^^^^^^^^^^^^^^^
  File "/home/py/.virtualenvs/djangocms/lib/python3.11/site-packages/djangocms_stories/views.py", line 69, in get_object
    obj = super().get_object()
          ^^^^^^^^^^^^^^^^^^^^
  File "/home/py/.virtualenvs/djangocms/lib/python3.11/site-packages/django/views/generic/detail.py", line 53, in get_object
    obj = queryset.get()
          ^^^^^^^^^^^^^^
  File "/home/py/.virtualenvs/djangocms/lib/python3.11/site-packages/django/db/models/query.py", line 638, in get
    raise self.model.MultipleObjectsReturned(
    ^

Exception Type: MultipleObjectsReturned at /en/conference/news/2025/01/28/save-the-date-28iphc/
Exception Value: get() returned more than one PostContent -- it returned 2!
Raised during: djangocms_stories.views.PostDetailView

[fsbraun]

@MacLake This indicates an invalid database state, e.g., if you used djangocms-stories with versioning first, and then disabled versioning. There should be maximum one (published) PostContent object per Post object.

To find the bug, we need to find how multiple PostContent objects got created? Any idea?

To fix your issue, you will need to delete all but one (public) PostContent objects per Post.