Confirming this is still an issue on v3 of the module. Patch provided for that version.
I don't have a fix, but I want to confirm that the error is still possible on 2.0.0--alpha1 even though the issue DWW mentions above is in that release.
Replicating the issue
Does anyone who is experiencing this issue have workflow enabled?
For me, having workflow enabled and saving in any state other than published seems to be the issue. Once I move the state to published, that error goes away.
The confusing part is that even while I'm still getting the error on the node, if I go to the group's list of nodes, the new node displays in that list. And, as in the issue's screenshots, the group name is listed just above the error. I see the relationship entity in the db.
Without Workflow
I turned off workflow moderation for this content type, created a new node and saved as unpublished and I did NOT get the error.
This issue just moved over from Group module issue queue. It looks like a duplicate of https://www.drupal.org/project/config_views/issues/3358929 🐛 Incompatible with Group 3.x Needs review
FYI The patch in comment #9 fixes the error message, but the prefix "field_" does not actually prepend the new field name after saving.
Also, the module is getting the prefix value from config in multiple other places, so it NEEDS to be set and not null.
I think the issue to fix is that the config value isn't getting set even though the module contains a default install config value of 'field_'
The line removed as the proposed fix for this issue was supposed to be removed as part of this: https://git.drupalcode.org/project/easy_breadcrumb/-/merge_requests/39/d...
It looks like it was accidentally re-added in a subsequent release.
Now that we return to getting the title value from `$title = (string) $entity->label();` AFTER the fix added from https://www.drupal.org/project/easy_breadcrumb/issues/3254436 → , the title returned from the titleResolver gets overwritten with the simple entity label.
I've tested the fix proposed here with a setting in the "Alternative title field name for breadcrumb" field and without and get the expected results in both cases. Without the fix here, I can only ever get the entity title value.