Call to a member function getConfigDependencyName() on a non-object in FieldConfigBase.php

I was running a complete migration with drush, all of which is succeeding except - d6_vocabulary_field_instance. All available migrations except book* and aggregator* are included in the manifest, which I've attached. #2368801 may be related, but I opened this separately since that was using the Migrate Update module and this is happening with drush.

I'm getting:

PHP Fatal error:  Call to a member function getConfigDependencyName() on a non-object in /var/www/tag1eight/drupal/core/lib/Drupal/Core/Field/FieldConfigBase.php on line 236

I set a break point at line 236 and saw the following on the command line:
array_flip(): Can only flip STRING and INTEGER values! EntityStorageBase.php:220

In PHPStorm, I see that $bundle_entity = null, and the $bundle_entity_type_id='node_type'

Here's the full output:

PHP Fatal error:  Call to a member function getConfigDependencyName() on a non-object in /var/www/tag1eight/drupal/core/lib/Drupal/Core/Field/FieldConfigBase.php on line 236
PHP Stack trace:
PHP   1. {main}() /home/melissa/.composer/vendor/drush/drush/drush.php:0
PHP   2. drush_main() /home/melissa/.composer/vendor/drush/drush/drush.php:16
PHP   3. Drush\Boot\DrupalBoot->bootstrap_and_dispatch() /home/melissa/.composer/vendor/drush/drush/drush.php:76
PHP   4. drush_dispatch($command = *uninitialized*, $arguments = *uninitialized*) /home/melissa/.composer/vendor/drush/drush/lib/Drush/Boot/DrupalBoot.php:46
PHP   5. call_user_func_array(*uninitialized*, *uninitialized*) /home/melissa/.composer/vendor/drush/drush/includes/command.inc:178
PHP   6. drush_command(*uninitialized*) /home/melissa/.composer/vendor/drush/drush/includes/command.inc:178
PHP   7. _drush_invoke_hooks($command = *uninitialized*, $args = *uninitialized*) /home/melissa/.composer/vendor/drush/drush/includes/command.inc:210
PHP   8. call_user_func_array(*uninitialized*, *uninitialized*) /home/melissa/.composer/vendor/drush/drush/includes/command.inc:359
PHP   9. drush_migrate_manifest($manifest = *uninitialized*) /home/melissa/.composer/vendor/drush/drush/includes/command.inc:359
PHP  10. Drupal\migrate\MigrateExecutable->import() /home/melissa/.composer/vendor/drush/drush/commands/core/migrate.d8.drush.inc:51
PHP  11. Drupal\migrate\Plugin\migrate\destination\EntityConfigBase->import($row = *uninitialized*, $old_destination_id_values = *uninitialized*) /var/www/tag1eight/drupal/core/modules/migrate/src/MigrateExecutable.php:285
PHP  12. Drupal\Core\Entity\Entity->save() /var/www/tag1eight/drupal/core/modules/migrate/src/Plugin/migrate/destination/EntityConfigBase.php:45
PHP  13. Drupal\Core\Config\Entity\ConfigEntityStorage->save($entity = *uninitialized*) /var/www/tag1eight/drupal/core/lib/Drupal/Core/Entity/Entity.php:325
PHP  14. Drupal\Core\Entity\EntityStorageBase->save($entity = *uninitialized*) /var/www/tag1eight/drupal/core/lib/Drupal/Core/Config/Entity/ConfigEntityStorage.php:232
PHP  15. Drupal\field\Entity\FieldConfig->preSave($storage = *uninitialized*) /var/www/tag1eight/drupal/core/lib/Drupal/Core/Entity/EntityStorageBase.php:395
PHP  16. Drupal\Core\Config\Entity\ConfigEntityBase->preSave($storage = *uninitialized*) /var/www/tag1eight/drupal/core/modules/field/src/Entity/FieldConfig.php:164
PHP  17. Drupal\field\Entity\FieldConfig->calculateDependencies() /var/www/tag1eight/drupal/core/lib/Drupal/Core/Config/Entity/ConfigEntityBase.php:309
PHP  18. Drupal\Core\Field\FieldConfigBase->calculateDependencies() /var/www/tag1eight/drupal/core/modules/field/src/Entity/FieldConfig.php:171
Drush command terminated abnormally due to an unrecoverable error.                                                                                [error]
Error: Call to a member function getConfigDependencyName() on a non-object in
/var/www/tag1eight/drupal/core/lib/Drupal/Core/Field/FieldConfigBase.php, line 236