Description of the need This is a long standing confusion. In Drupal there are multiple issues for this:
- https://www.drupal.org/project/drupal/issues/502430
- https://www.drupal.org/project/drupal/issues/848470
- https://www.drupal.org/project/drupal/issues/2862291
The first issue describes it well:
It is somewhat disconcerting to users who have the 'administer book outlines' permission to see the 'outline' tab and 'outline' fieldset on every single node type, regardless of whether that node type has been configured to be allowed in books. I can see a use-case where that might be a desired feature, but i think its probably relatively rare.
Note, that book module seems to be the oddball here. If you disable menus for a content type not even user 1 has ability to add them to a menu from within the content type.
Proposed solution
Create an additional checkbox in the content/book/settings
form that when checked allows book outlines for any content type, not just the designated book-types. By default this is checked, so that any current sites that might rely on "seeing outline information on all content types regardless of config settings" won't be broken by this after upgrading.
Recent comments
Thanks! The site was on PHP 7.0. With assistance from my hosting provider, I updated to PHP 7.4 and now I have access to the site again. No database re-import required.
Locked out of site after updating modules
Thank you very much. I will follow your advice.
Locked out of site after updating modules
The best you can do is test and report. If you find a contrib that doesn't work in php 8.3, create an issue in its queue so it gets fixed. In my experience, I've found that 7.4 is safest...
Locked out of site after updating modules