Error message

Notice: Array to string conversion in views_arg_load() (line 473 of /home/schoolprd/wardpto/drupal-7.15/sites/all/modules/views/views.module).
Notice: Array to string conversion in views_arg_load() (line 473 of /home/schoolprd/wardpto/drupal-7.15/sites/all/modules/views/views.module).
Notice: Array to string conversion in views_arg_load() (line 473 of /home/schoolprd/wardpto/drupal-7.15/sites/all/modules/views/views.module).
Notice: Array to string conversion in views_arg_load() (line 473 of /home/schoolprd/wardpto/drupal-7.15/sites/all/modules/views/views.module).