yeah a friend told me about that a few hours ago, i check a bit and found this : https://support.humblebundle.com/hc/en-us/articles/206159007-Why-am-I-receiving-the-error-message-Keys-are-temporarily-exhausted-for-this-product- i believe all we have to do is waiting until they fix this, and hope it will be quick^^

Thank you kind sir ! due to personnal playtime i was afraid i would not be able to complete the rift, but now i have some hope ill can !