Time slot bookings not working

Hello,

Im trying to book by time slots instead of by day, but after setting it up and i try to book by a time slot, it keeps saying results cant be loaded. Is this a bug?? Can you please fix because nobody can book on my site now.

Please edit this listing and make sure that the Booking From, Booking To, and Slot Duration fields are not empty; these 3 details are required to generate a list of time slots for each date.