Warning: array_flip(): Can only flip string and integer values, entry skipped in Drupal\Core\Entity\EntityStorageBase->loadMultiple() (line 278 of core/lib/Drupal/Core/Entity/EntityStorageBase.php).
Deprecated function: trim(): Passing null to parameter #1 ($string) of type string is deprecated in boell_event_registration_form_alter() (line 112 of modules/custom/boell_event_registration/boell_event_registration.module).