When loading an entity from the DB, you may get this error message 'Attempt to set null on non-nullable field' (DBS_SetFieldExcpetion::TYPE_NULL) if the DB column produces null and your entity is not marked with ALLOW_NULL. more⇛

The 'Field not available on this instance:field' is a common one and can have several different meanings. It is unfortunately not easy, or possible, for Persephone to determine exactly why the field is not available. more⇛