'AttributeError' when accessing Change Log post-upgrade to 3.0

[michalceb]

Hello,

I can't log this as issue, as I am unable to replicate this on the dev instance, however, I hope someone can assist.

After upgrading to 3.0 from 2.11.12, I am unable to load Change Log page.
The summary Change Log view on Home page is working correctly and I can open a specific entry from there and from a specific object, however, main list is not loading with the below error:

Server Error

There was a problem with your request. Please contact an administrator.

The complete exception is provided below:

<class 'AttributeError'>

'NoneType' object has no attribute '_meta'

Python version: 3.8.2
NetBox version: 3.0.0

If further assistance is required, please post to the NetBox mailing list.
Home Page

Thanks in advance for all help.

[candlerb]

Can you get a full backtrace? The easiest way is to set up the EMAIL and ADMINS section in configuration.py, then it will be E-mailed to you whenever this happens.

Otherwise, you can set DEBUG = True and you should get a backtrace to the screen, and you can copy-paste the text from there (which would be much preferred over a graphical screenshot)

[michalceb]

I was meant to get the email functionality set up, which I have now done.

Here is the Traceback:
Traceback (most recent call last):
File "/opt/netbox/venv/lib/python3.8/site-packages/django/core/handlers/exception.py", line 47, in inner
response = get_response(request)
File "/opt/netbox/venv/lib/python3.8/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/python3.8/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/python3.8/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 189, in get
return render(request, self.template_name, context)
File "/opt/netbox/venv/lib/python3.8/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/python3.8/site-packages/django/template/loader.py", line 62, in render_to_string
return template.render(context, request)
File "/opt/netbox/venv/lib/python3.8/site-packages/django/template/backends/django.py", line 61, in render
return self.template.render(context)
File "/opt/netbox/venv/lib/python3.8/site-packages/django/template/base.py", line 170, in render
return self._render(context)
File "/opt/netbox/venv/lib/python3.8/site-packages/django/test/utils.py", line 100, in instrumented_test_render
return self.nodelist.render(context)
File "/opt/netbox/venv/lib/python3.8/site-packages/django/template/base.py", line 938, in render
bit = node.render_annotated(context)
File "/opt/netbox/venv/lib/python3.8/site-packages/django/template/base.py", line 905, in render_annotated
return self.render(context)
File "/opt/netbox/venv/lib/python3.8/site-packages/django/template/loader_tags.py", line 150, in render
return compiled_parent._render(context)
File "/opt/netbox/venv/lib/python3.8/site-packages/django/test/utils.py", line 100, in instrumented_test_render
return self.nodelist.render(context)
File "/opt/netbox/venv/lib/python3.8/site-packages/django/template/base.py", line 938, in render
bit = node.render_annotated(context)
File "/opt/netbox/venv/lib/python3.8/site-packages/django/template/base.py", line 905, in render_annotated
return self.render(context)
File "/opt/netbox/venv/lib/python3.8/site-packages/django/template/loader_tags.py", line 150, in render
return compiled_parent._render(context)
File "/opt/netbox/venv/lib/python3.8/site-packages/django/test/utils.py", line 100, in instrumented_test_render
return self.nodelist.render(context)
File "/opt/netbox/venv/lib/python3.8/site-packages/django/template/base.py", line 938, in render
bit = node.render_annotated(context)
File "/opt/netbox/venv/lib/python3.8/site-packages/django/template/base.py", line 905, in render_annotated
return self.render(context)
File "/opt/netbox/venv/lib/python3.8/site-packages/django/template/loader_tags.py", line 150, in render
return compiled_parent._render(context)
File "/opt/netbox/venv/lib/python3.8/site-packages/django/test/utils.py", line 100, in instrumented_test_render
return self.nodelist.render(context)
File "/opt/netbox/venv/lib/python3.8/site-packages/django/template/base.py", line 938, in render
bit = node.render_annotated(context)
File "/opt/netbox/venv/lib/python3.8/site-packages/django/template/base.py", line 905, in render_annotated
return self.render(context)
File "/opt/netbox/venv/lib/python3.8/site-packages/django/template/loader_tags.py", line 62, in render
result = block.nodelist.render(context)
File "/opt/netbox/venv/lib/python3.8/site-packages/django/template/base.py", line 938, in render
bit = node.render_annotated(context)
File "/opt/netbox/venv/lib/python3.8/site-packages/django/template/base.py", line 905, in render_annotated
return self.render(context)
File "/opt/netbox/venv/lib/python3.8/site-packages/django/template/loader_tags.py", line 62, in render
result = block.nodelist.render(context)
File "/opt/netbox/venv/lib/python3.8/site-packages/django/template/base.py", line 938, in render
bit = node.render_annotated(context)
File "/opt/netbox/venv/lib/python3.8/site-packages/django/template/base.py", line 905, in render_annotated
return self.render(context)
File "/opt/netbox/venv/lib/python3.8/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/python3.8/site-packages/django/template/backends/django.py", line 61, in render
return self.template.render(context)
File "/opt/netbox/venv/lib/python3.8/site-packages/django/template/base.py", line 170, in render
return self._render(context)
File "/opt/netbox/venv/lib/python3.8/site-packages/django/test/utils.py", line 100, in instrumented_test_render
return self.nodelist.render(context)
File "/opt/netbox/venv/lib/python3.8/site-packages/django/template/base.py", line 938, in render
bit = node.render_annotated(context)
File "/opt/netbox/venv/lib/python3.8/site-packages/django/template/base.py", line 905, in render_annotated
return self.render(context)
File "/opt/netbox/venv/lib/python3.8/site-packages/django/template/defaulttags.py", line 211, in render
nodelist.append(node.render_annotated(context))
File "/opt/netbox/venv/lib/python3.8/site-packages/django/template/base.py", line 905, in render_annotated
return self.render(context)
File "/opt/netbox/venv/lib/python3.8/site-packages/django/template/defaulttags.py", line 167, in render
values = list(values)
File "/opt/netbox/venv/lib/python3.8/site-packages/django_tables2/rows.py", line 244, in items
column.current_value = self.get_cell(column.name)
File "/opt/netbox/venv/lib/python3.8/site-packages/django_tables2/rows.py", line 197, in get_cell
return self._get_and_render_with(
File "/opt/netbox/venv/lib/python3.8/site-packages/django_tables2/rows.py", line 173, in _get_and_render_with
return render_func(bound_column, value)
File "/opt/netbox/venv/lib/python3.8/site-packages/django_tables2/rows.py", line 206, in _call_render
content = call_with_appropriate(bound_column.render, render_kwargs)
File "/opt/netbox/venv/lib/python3.8/site-packages/django_tables2/utils.py", line 572, in call_with_appropriate
return fn(**kwargs)
File "/opt/netbox/netbox/utilities/tables.py", line 240, in render
return content_type_name(value)
File "/opt/netbox/netbox/utilities/utils.py", line 310, in content_type_name
meta = contenttype.model_class()._meta

Exception Type: AttributeError at /extras/changelog/ Exception Value: 'NoneType' object has no attribute '_meta'

[michalceb]

Looks like there is an issue now open for something similar #7082. Although the only page that is affected on our instance is the Change Log.

[michalceb]

For anyone experiencing this issue in 3.0.0, I can confirm that this issue was resolved in 3.0.1.