Reverse for 'managedfile' not found. 'managedfile' is not a valid view function or pattern name.

[cmdrrobin]

We have two datasources defined in our Netbox environment. (production and test)
Both environments have the same issue:

NoReverseMatch at /core/data-sources/2/delete/
Reverse for 'managedfile' not found. 'managedfile' is not a valid view function or pattern name.
Request Method:	GET
Request URL:	https://netbox-sandbox.apps.systems.local/core/data-sources/2/delete/?return_url=/core/data-sources/
Django Version:	5.2.2
Exception Type:	NoReverseMatch
Exception Value:	
Reverse for 'managedfile' not found. 'managedfile' is not a valid view function or pattern name.
Exception Location:	/opt/netbox/venv/lib/python3.12/site-packages/django/urls/resolvers.py, line 831, in _reverse_with_prefix
Raised during:	core.views.DataSourceDeleteView
Python Executable:	/opt/netbox/venv/bin/python
Python Version:	3.12.3
Python Path:	
['/opt/netbox/netbox/',
 '/usr/lib/python312.zip',
 '/usr/lib/python3.12',
 '/usr/lib/python3.12/lib-dynload',
 '/opt/netbox/venv/lib/python3.12/site-packages']
Server time:	Wed, 02 Jul 2025 09:33:13 +0000

I have enabled debug in our testenvironment:

Internal Server Error: /core/data-sources/2/delete/
Traceback (most recent call last):
  File "/opt/netbox/netbox/netbox/middleware.py", line 132, in __call__
    username = request.META[self.header]
               ~~~~~~~~~~~~^^^^^^^^^^^^^
KeyError: 'HTTP_REMOTE_USER'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/opt/netbox/netbox/netbox/views/generic/object_views.py", line 421, in get
    dependent_objects = self._get_dependent_objects(obj)
                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/netbox/netbox/netbox/views/generic/object_views.py", line 378, in _get_dependent_objects
    collector.collect([obj])
  File "/opt/netbox/venv/lib/python3.12/site-packages/django/db/models/deletion.py", line 350, in collect
    raise ProtectedError(
django.db.models.deletion.ProtectedError: ("Cannot delete some instances of model 'DataSource' because they are referenced through protected foreign keys: 'ManagedFile.data_source'.", {<ManagedFile: tenant.py>, <ManagedFile: device_oob.py>})

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/opt/netbox/venv/lib/python3.12/site-packages/django/core/handlers/exception.py", line 55, in inner
    response = get_response(request)
               ^^^^^^^^^^^^^^^^^^^^^
  File "/opt/netbox/venv/lib/python3.12/site-packages/django/core/handlers/base.py", line 197, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/netbox/venv/lib/python3.12/site-packages/django/views/generic/base.py", line 104, in view
    return self.dispatch(request, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/netbox/netbox/netbox/views/generic/base.py", line 26, in dispatch
    return super().dispatch(request, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/netbox/netbox/utilities/views.py", line 125, in dispatch
    return super().dispatch(request, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/netbox/netbox/utilities/views.py", line 39, in dispatch
    return super().dispatch(request, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/netbox/venv/lib/python3.12/site-packages/django/views/generic/base.py", line 143, in dispatch
    return handler(request, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/netbox/netbox/netbox/views/generic/object_views.py", line 423, in get
    return self._handle_protected_objects(obj, e.protected_objects, request, e)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/netbox/netbox/netbox/views/generic/object_views.py", line 397, in _handle_protected_objects
    handle_protectederror(protected_objects, request, exc)
  File "/opt/netbox/netbox/utilities/error_handlers.py", line 40, in handle_protectederror
    dependent_objects.append(f'<a href="{dependent.get_absolute_url()}">{escape(dependent)}</a>')
                                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/netbox/netbox/core/models/files.py", line 68, in get_absolute_url
    return reverse('core:managedfile', args=[[self.pk](http://self.pk/)])
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/netbox/venv/lib/python3.12/site-packages/django/urls/base.py", line 98, in reverse
    resolved_url = resolver._reverse_with_prefix(view, prefix, *args, **kwargs)
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/netbox/venv/lib/python3.12/site-packages/django/urls/resolvers.py", line 831, in _reverse_with_prefix
    raise NoReverseMatch(msg)
django.urls.exceptions.NoReverseMatch: Reverse for 'managedfile' not found. 'managedfile' is not a valid view function or pattern name.

Our test environment runs Netbox version 4.3.2. Production still runs 3.7.8, but are planning to upgrade. Both uses Netbox container image.

[cmdrrobin]

Although I don't think this is the solution, but I have tested on one of the defined datasources.

In the database I have executed the following command:

DELETE FROM core_managedfile WHERE data_source_id=(
  SELECT id FROM core_datasource WHERE name='git-reports'
);

After that I could remove the datasource from UI.