prestashop "This voucher does not exists."

Hello, I've installed the awocoupon module, activated it and now I'm creating some coupon codes but on the checkout page when i insert the code I always get: "THERE IS 1 ERROR This voucher does not exists." no matter wich type of discount I'm trying to trigger.
What am I missing?

Sorry, I already searched on the forum but I missed this post: https://awodev.com/forum/awocoupon/help-section/prestashop-156-voucher-does-not-exists
forcing the regeneration of class_index.php did the trick. ty an sry again.