Why does up2date say that my subscription number is invalid after I enter it?

Subscription numbers are intended to activate your subscription. Once this has been done, you will not need to use them again. If you have entered your number more than once, you will receive an error that your number is invalid. Also, if you enter it at www.redhat.com/activate , it will post an error that it has already been registered. You should also ensure that you are entering the number correctly as this will cause the same error.

If you are re-registering your system and have already activated your subscription number, select the option beneath the subscription number field. You will either have an option for Use one of my existing active subscriptions or I do not have a subscription number.