Validate button returns Validation failed Cannot check version: TypeError: undefined is not an object (evaluating 't.setAttribute')

JupyterHub is running on k8s cluster and users pods are based on docker image with FROM quay.io/jupyter/minimal-notebook:hub-4.1.3 Hub image in helm chart values.yaml is a docker image with FROM jupyterhub/k8s-hub:3.0.3

Operating system

Ubuntu 22.04.2 LTS

`nbgrader --version`

0.9.1

`jupyterhub --version` (if used with JupyterHub)

4.1.3

`jupyter notebook --version`

7.1.2

Expected behavior

When clicking "validate" button, it should be successful.

Actual behavior

When clicking "validate" button I get "Validation failed" with such reason: Cannot check version: TypeError: undefined is not an object (evaluating 't.setAttribute')

If I validate notebook in jupyterhub terminal by the command nbgrader validate notebook_name.ipynb, it finishes with success

I found code for this error dialog and checked if I have validate_assignment server extension. I checked it by running the command jupyter server extension list in terminal and got

...
nbgrader.server_extensions.validate_assignment enabled
    - Validating nbgrader.server_extensions.validate_assignment...
Extension package nbgrader.server_extensions.validate_assignment took 0.6952s to import
      nbgrader.server_extensions.validate_assignment  OK
...

Steps to reproduce the behavior

Click validate button in any notebook

jupyter / nbgrader