ValueError "User.config" must be a "UserConfig" instance

[MakoWish]

I would appreciate some help with this. A colleague at work pointed me to NetBox, and I wanted to test it out. I am attempting to get up and running in my lab, and at the point in the documentation where we test via python3 manage.py runserver 0.0.0.0:8000 --insecure, I get a login page, but after entering the credentials I set, I get the error below.

Server Error

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

The complete exception is provided below:

<class 'ValueError'>

Cannot assign "<netbox.config.Config object at 0x7ace1d5d3680>": "User.config" must be a "UserConfig" instance.

Python version: 3.12.3
NetBox version: 4.1.3
Plugins: None installed

If further assistance is required, please post to the NetBox discussion forum on GitHub.
Home Page

[KriKrixs]

Hi @MakoWish

I had the same issue and resolved it by deleting the database in Postgre and recreate it using the documentation.

[termark]

Thank you, this worked for me as well

[MakoWish]

Thank you, @KriKrixs . Since this was a new build in a lab environment, I just blew the entire VM away and started from scratch last night. I am no longer getting that error. Now... to get LDAP authentication to work! Hahaha

[KriKrixs]

Good luck mate 😂, have a nice day !

[MakoWish]

I actually got it working just a few minutes later. I had mistyped a DN. I should have copy/pasted it in the first place.

[lgt-bu]

Hi, I recently upgraded from 3.6.x to 4.1.6 (i did requisite path from 3.6.x to 3.7.8, then onwards to 4.1.6) and since then, adding a new user we get that message above when they try to login.

On our system:

Server Error

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

The complete exception is provided below:

<class 'ValueError'>

Cannot assign "<netbox.config.Config object at 0x7f41c868cdf0>": "User.config" must be a "UserConfig" instance.

Python version: 3.10.0
NetBox version: 4.1.6
Plugins: 
  netbox_reorder_rack: 1.1.3
  netbox_topology_views: 4.1.0

If further assistance is required, please post to the [NetBox discussion forum](https://github.com/netbox-community/netbox/discussions) on GitHub.
[Home Page](https://netbox.ourserver.uk)

I'm not confident with a resolution of just starting again. Nor with the idea that I just delete the database. Where is that solution and how safe? We are not using the ldap plugin. It's just local accounts on the box.

[dbrummer]

I noticed a similar issue with trying to add an additional superuser via the Helm chart values.yaml. It created the user but didn't create the required entry in public.users_userconfig. I had to manually enter a new row with the data column set to {} and user_id as the id of the newly created user. This is was on NetBox Community v4.2.4-Docker-3.2.0 and I'm looking into a potential fix.

[maxabaumgarten]

ran into the same thing. your fix works

NetBox release | NetBox Community v4.2.5-Docker-3.2.0 (2025-03-06)
Python Version: 3.12.3
Django Verison 5.1.7
PostgreSQL 17.3 on aarch64-unknown-linux-gnu

[Guruleenyc]

I just experienced this error for a new docker installation on Unraid. The error occurs when I try to login to Netbox. How can I resolve?

[Fubs]

@dbrummer's fix worked for me. If you can get into the postgres database then you should be able to fix with the query INSERT INTO users_userconfig VALUES (0, '{}', 1);.

I'm running this docker compose file

$ cat docker-compose.yml 
---
services:
  netbox:
    image: lscr.io/linuxserver/netbox:latest
    container_name: netbox
    environment:
      - PUID=1000
      - PGID=1000
      - TZ=<my timezone>
      - SUPERUSER_EMAIL=<my email>
      - SUPERUSER_PASSWORD=<my superuser password>
      - ALLOWED_HOST=<my allowed host>
      - DB_NAME=netbox
      - DB_USER=netbox
      - DB_PASSWORD=<password for netbox postgres db>
      - DB_HOST=postgres.myserverhostname.local
      - DB_PORT=5432
      - REDIS_HOST=redis.myserverhostname.local
      - REDIS_HOST=6379
      - REDIS_DB_TASK=5
      - REDIS_DB_CACHE=6
    volumes:
      - /storage_ssd/netbox/config:/config
    ports:
      - 33006:8000
    restart: unless-stopped

Before starting netbox for the first time, I made a postgres role called "netbox" and a database called "netbox" owned by the new netbox role. Then I ran docker compose up, let it populate the postgres database and make the config files, then stopped the docker compose service. Then, I connected to the database with

$ psql -U postgres -h postgres.myserverhostname.local netbox

ran the insert query

psql (17.5)
Type "help" for help.

netbox=# INSERT INTO users_userconfig VALUES (0, '{}', 1);

restarted the docker compose service, and after it started up I was able to login with the username admin and the <my superuser password> from the docker compose file.