When Rambox tries to charge your subscription and, for any reason, the transaction is rejected, a notification will be displayed informing that we were unable to renew your license:

In this case, we'll try your payment again over the next few days. You may need to update your payment details in order to keep your Pro features if payment is not effected.

If your payments continue failing, and you do not update your payment details within the next 7 days, a new notification will be displayed inviting you to re-subscribe to a plan or buy the Lifetime license by going to the Billing Section. Otherwise, you may switch to the Basic Plan.

After you re-subscribe, you shouldn't see this notification. However, occasionally, our payment and license services take some time to synchronize, and this could cause unexpected "License expired" notifications, so please wait a few hours until payment is synchronized. If you keep seeing this notification, your license expired even you re-subscribed, or you have any trouble with your license, please contact us through a support ticket. 

Keep in mind that if you purchase a Lifetime subscription, your license should NEVER get expired. As said, if you still have some trouble, please contact customer support at support@rambox.app.