Hello,
If you don't resume the subs for Fences 5, it may stop working. But, your Fences 4 should still work.
https://support.stardock.com/space/SHC/1544388616/Stardock+Software+Subscriptions
How to cancel \ pause a subscription auto-payment
On your subscription page, click “Manage” and in the pop-up window, near the top right corner, click “Cancel Auto Payment” and this will turn off the auto-renewal. Please note that if you do not renew your subscription on the renewal date provided by the subscription overview page, your software may cease to function and/or no longer receive feature updates or patches.
Thank you.
Basj,
Stardock Community Assistant.