Trying to get property of non-object in relation_endpoint_get_endpoint_entity_types()

Steps to reproduce:

1. Have a database with some basic node<->node relations in it.
2. Create relation view.
3. Add "endpoints" field to view.
4. See error.

Notice: Trying to get property of non-object in _relation_endpoint_get_endpoint_entity_types() (line 231 of /home/naught101/Documents/coding/drupal/d7/sites/all/modules/relation/relation_endpoint.module).
Warning: Invalid argument supplied for foreach() in _relation_endpoint_get_endpoint_entity_types() (line 232 of /home/naught101/Documents/coding/drupal/d7/sites/all/modules/relation/relation_endpoint.module).
Notice: Undefined variable: endpoint_entity_types in _relation_endpoint_get_endpoint_entity_types() (line 236 of /home/naught101/Documents/coding/drupal/d7/sites/all/modules/relation/relation_endpoint.module).
Warning: Invalid argument supplied for foreach() in relation_endpoint_field_formatter_settings_form() (line 198 of /home/naught101/Documents/coding/drupal/d7/sites/all/modules/relation/relation_endpoint.module).
Notice: Undefined variable: element in relation_endpoint_field_formatter_settings_form() (line 212 of /home/naught101/Documents/coding/drupal/d7/sites/all/modules/relation/relation_endpoint.module).

This doesn't actually appear to screw up the view results, but it's annoying as hell, and makes page loads really slow.