Archive access follows your plan
Every plan gets each new weekly workout. What differs is how deep into the back-catalog you can go:
Essentials — the most recent 12 months
Plus — the most recent 3 years
Max — everything, back to the very first workout
When you open a case outside your window, you'll see a notice naming the plan that unlocks it instead of the case content. Nothing is wrong with your account — that case is simply beyond your plan's archive range.
How to unlock more
Go to My Account → Change plan. Upgrades take effect immediately: you pay only the prorated difference for the rest of your year, and the wider archive opens the moment it goes through.
Other things that can look like a lock
Group seats: your access level is set by your group's plan. If you need deeper archive access, ask your group leader about upgrading the group.
Free trials unlock a limited number of cases — see How the free trial works.
Lapsed membership: if your membership ended, you'll see a welcome-back page when you sign in. Rejoining picks your history back up — nothing is deleted.