If you bought Pro a year ago, your email address won't be recognised because it won't be in the database anymore.
An email address will only be recognised if the user's Pro benefits (ie their entitlement to free updates & email support) are still current.

A year ago, there was only the option to buy Pro with 6 months worth of free updates & email support. Your Pro benefits would have expired 6 months after you bought Pro.

Whatever Pro installers you download during the time that your Pro's current are yours to use till the cows come home. But you need to save those installers, if you want to keep using them.