The app is designed and intended for only one active profile per device (Mobile or tablet). If you have ever used more than one Fever profile on your device, the use of vouchers gets automatically blocked and you will never be able to use our discount coupons on those profiles.
This happens, for instance, when users sign in with Facebook or Google interchangeably: two different profiles are created. Or if a relative/friend of yours has used your device to check his profile, none of you will be able to redeem codes anymore.
When this happens, we must delete all the profiles used to sign in from that device except one, otherwise vouchers cannot be used.
If that is your case, please send an email from the account you want to delete to firstname.lastname@example.org explaining the situation.