Handling Issues in Migration
Fix "non-existent config entity name returned by FieldStorageConfigInterface::getBundles()"
Normally it will show that a field belongs to a non existing bundle for a node, comment etcetra in log post migration.
Solving a field that does not belong to non existent bundle in a node, example, field_agenda present in a non existent bundle makemeeting of node type
$key_value_factory = \Drupal::service("keyvalue");
$field_map_kv_store = $key_value_factory->get("entity.definitions.bundle_field_map");
$node_map = $field_map_kv_store->get("node");