Datepicker Calendars won't pop-up

The Vik Rent Items plugin has some WordPress Widgets as well as some Views that use the datepicker calendars for letting the customers choose the Pick-up and Drop-off Dates.

When such fields get the focus by clicking on them, the datepicker calendar should pop up. If the calendars are not being displayed when clicking on those fields then there is a Javascript conflict on your website with other plugins that is breaking this function.