The custom behat method stored in tests/behat/lib_behattest.php defines items using, sometimes, bad mform element names.

For instance:

• for age plugin it is used lowerbound_year instead of lowerboundyear (and similar);
• for autofill plugin it is used element01_select instead of element01select (and similar);
• for date plugin it is used lowerbound_day instead of lowerboundday (and similar);
• for datetime plugin it is used lowerbound_day instead of lowerboundday (and similar);
• for recurrence plugin it is used lowerbound_day instead of lowerboundday (and similar);
• for shortdate plugin it is used lowerbound_day instead of lowerboundday (and similar);
• for time plugin it is used lowerbound_day instead of lowerboundday (and similar).