Cannot create or edit any coupons in Membership2


after installing the beta version 1.1.2 beta5 to fix a problem with the Stripe payment gateway and the coupons, now that I wanted to add a new coupon and/or edit others, I cannot add a new or edit an old coupon anymore, at all.

As I wanted to offer a special Christmas deal today and send out a new campaign, this is really urgent and frustrating because the support told me before this new version would have fixed the problem of coupons that beforehand were behaving differently depending on whether being used for Paypal or Stripe.

Could you please help me ASAP and tell me how to fix this issue?

Thanks very much.