Field collection unique

Correct me if I'm wrong, but since there are no instructions I guessed that in order to validate if the combination of values in few fields in the node is unique I did this:
1) Installed the Field Collection module
2) created a Field collection with few fields (one of the fields have multiple values)
3) Added a validation rule - "Field collection unique" to a newly created field collection

Validation doesn't work:
1) I'm allowed to create as many duplicate nodes as I want with exactly the same values in each of them
2) I get this notice:
Notice: Undefined property: stdClass::$field_name in field_validation_field_collection_unique_validator->validate() (line 36 of /.../.../.../sites/all/modules/field_validation/field_validation_extras/plugins/validator/field_validation_field_collection_unique_validator.inc).

I would use the Unique Field module, but Drupal 7 version doesn't work well with multivalued fields. It doesn't check each value in the field separately. Field Validation module checks each value of the multivalued field beautifully, but I need to check it in combination with few other fields, that is why I tried "Field collection unique" rule.