My dblogs are showing many rows of this this error constantly (several times per hour):
Warning: array_key_exists() expects parameter 2 to be array, null given in theme_image_formatter() (line 605 of /path-to-drupal/modules/image/image.field.inc).
The only issue I could find for it was posted for Drupal core -- http://drupal.org/node/1902444 -- but it was quickly dismissed as being a Views issue instead. However, there is no indication how to fix it, and I haven't found any issues in Views about it.
Does anyone know what to do about this?