Unable to save 'access unpublished' setting form - TypeError: Drupal\Core\Render\Element::children(): Argument #1 ($elements) must be of type array, null given

This issue is only happening with Drupal core 10.2 and it is working fine with Drupal 10.0, do we have any patch for this issue?

I am able to replicate the issue.

Let me try to work on this.

DamienMcKenna → changed the visibility of the branch 3421309-unable-to-save to hidden.

The problem is the validation on the modify_http_headers field, if that's removed the form can save correctly.

This patch is a bandaid that lets the settings form save, but it needs a proper fix that uses the correct validation logic.

Thank you @DamienMcKenna for this patch and all that you do! The patch works for me!

The reason of this error is that module settings form uses ListItemBase::validateAllowedValues method as validation callback. But at the last versions of Drupal allowed values form of list fields was totally refactored. See this core commit https://git.drupalcode.org/project/drupal/-/commit/693ced9cd830f9b1d0942...
So to fix thie we need to either refactor module settings form to use the same approach as list fileds or copy the old validation callback to SettingsForm class. Unfortunately I can't do this because on my current froject we don't use headers settings, and in my case patch from #7 solved my problem

I can confirm the patch from #7 resolves the issue, but we will need a long term fix to add the validation correctly. Going to get this issue some attention as this module was a module of the week on Talking Drupal. Thanks All!