Gravity Form Malfunctioned with Coupon Code add on

[JohnyMax (Vida Cleaners)]

I’m using gravity form pro (elite version) with coupon code addon. Where I’ve added multiple discount fields with conditions having X% of discount. As well as coupon code field.

It was working fine but suddenly form became display none and in console it’s giving me this error.

[Error] TypeError: “#gf_coupon_codes_{0}”.format is not a function. (In ‘“#gf_coupon_codes_{0}”.format(r)’, ‘“#gf_coupon_codes_{0}”.format’ is undefined)
(anonymous function) (gp-ecommerce-fields.min.js:1:4492)
dispatch (jquery.min.js:2:40041)
trigger (jquery.min.js:2:70130)
(anonymous function) (jquery.min.js:2:70734)
each (jquery.min.js:2:3134)
(anonymous function) (book-now:2994)
dispatchEvent
trigger (gravityforms.min.js:1:7726)
(anonymous function) (gravityforms.min.js:1:46580)
e (jquery.min.js:2:27034)
(anonymous function) (jquery.min.js:2:27332)

Removing discount and coupon code fields from form fixes the error. How to fix this?

[richardw8k (Richard Wawrzyniak (Gravity Forms))]

The format function was removed in Gravity Forms 2.8, so add-ons that used that function have been updated to use a different function. The error you are seeing indicates your site is running an outdated version of an add-on, GP eCommerce Fields. You can resolve the error by updating the plugins on your site to the latest versions.