When I try to upgrade my wiki l receive an error message that states my wiki already has an active subscription.

We are thrilled to give educators the opportunity to use a PBwiki gold wikis however after your free upgrade expires we do not offer a second a second free upgrade.

After the one year upgrade period, your wiki will be downgraded to a free account. We have not and will never delete your data, but as a free wiki, you won't be able to upload more files above the 10MB quota.