Import error: Feeds item: This field can only contain one value

I think that you might have accidentally reversed a config update. In feeds_post_update_ensure_feeds_item_storage_config_cardinality_is_unlimited() the cardinality of all feeds_item fields were set to unlimited. This resulted into a change in all field.storage.*.feeds_item configuration items. But if you had done a config import after running database updates, then the change coming from that update got reversed.

Solution:

1. If you manage the config files in yml files, go through every field.storage.*.feeds_item.yml file and set 'cardinality' to -1.
2. After that, do a config import.

For example, field.storage.node.feeds_item.yml could then look like this:

uuid: fca90d5d-2059-40ba-b99c-76b7ead03233
langcode: nl
status: true
dependencies:
  module:
    - feeds
    - node
id: node.feeds_item
field_name: feeds_item
entity_type: node
type: feeds_item
settings:
  target_type: feeds_feed
module: feeds
locked: false
cardinality: -1
translatable: false
indexes: {  }
persist_with_no_fields: false
custom_storage: false

Note: the same question has been asked recently in 💬 feeds_item this field cannot hold more than 1 values. Fixed .

MegaChriz, you are the best!
That really makes sense. In the past I wasn't aware of this effect. And indeed I see the cardinality: 1 in the config files.
That makes me think what else might be mixed up in my sites...

Many thanks for your quick response.

Automatically closed - issue fixed for 2 weeks with no activity.