OpenCart Community

I created a coupon with 10% discount and when I try to apply it from cart page it says "Success: Your coupon discount has been applied!" but discount doesn't shown or calculated. I am using version 2.1.0.2 with default theme.

UPDATE: I've just made a fresh install and realised if I disable Coupon from Order Totals and then reanable it it stops working. Does anybody have an idea?

I've just discovered the problem. It's a bug!
coupon_sort_order value under oc_setting table returns null value when you reenable it.