If you have an active subscription and you suddenly notice the better balance training videos are re-locked, the first thing to do is double-check your subscription.
Go to Settings
Click on your Apple ID at the top
Click on "Subscriptions"
Confirm the ZIBRIO Better Balance Training appears under the ACTIVE subscriptions.
If your subscription shows as INACTIVE , then your payment may have failed or the subscription was canceled.
If your subscription shows as ACTIVE, then there was an issue at the time of renewal within the BalanceCoach app. Your subscription renewed through the store but our app isn't responding as it should. We are actively working on this and will be publishing a fixed app version soon. In the meantime, please report this to us via firstname.lastname@example.org so we can grant you access. Thank you for your patience with us.