Site Report log shows this error occurs hundreds of times a day on every page

Issue Summary

Undefined property: stdClass::$views_php_3 in views_php_handler_field->render() (line 223 of /www/html/10/10facts.com.com/sites/all/modules/views_php/plugins/views/views_php_handler_field.inc)

Line 223 has

$value = check_plain($values->{$this->field_alias});

I've even tried deleting that line and it still has that error every time someone accesses a page. I have no idea what this means. Thanks.