I'm having troubles enabling Content Moderation Module (content_moderation) on a Drupal 8.7.8 site.
During installation everything seems fine,
drush en content_moderation finishes without errors, workflows module is already enabled before.
After install the editorial workflow is missing, but it's possible to create a new content moderation workflow.
All role permissions are available and the Moderation State widget shows up on nodes of the selected types. But using the widget has no effect, nodes don't get published or unpublished.
The database tables for Content Moderation are created properly (ie. content_moderation_state and three more with similar names).
Also the view moderated_content shows "Broken/missing handler" where the filter criteria "Content revision: Moderation state (exposed)" and "Content revision: Moderation state (<> Published)" are supposed to be.
Clicking the Broken/missing handler fields shows some details for the two broken handlers:
The handler for this item is broken or missing. The following details are available: id: moderation_state_1 table: node_field_revision field: moderation_state relationship: none group_type: group admin_label: operator: not in group: 1 exposed: is_grouped: entity_type: node plugin_id: moderation_state_filter Enabling the appropriate module may solve this issue. Otherwise, check to see if there is a module update available.
Second field shows this info:
id: moderation_state table: node_field_revision field: moderation_state relationship: none group_type: group admin_label: operator: in group: 1 exposed: 1 is_grouped: entity_type: node plugin_id: moderation_state_filter
I also can't add any moderation state related fields to the view like "Moderation state". The fields do not show up in the "Add fields" dialog.
I'm having no problems setting up Content Moderation on a vanilla Drupal 8.7.8 it just fails on this existing site (same version).
I already tried reverting the site and reinstalling workflows and content_moderation on different ways, with drush and manually. I uninstalled all custom modules and patches and reinstalled content_moderation.
Are there any modules (except workbench) or settings known to cause problems with Content Moderation?
Any ideas what could be causing the problem or where to start looking?
Thanks a lot!