s2Member v220421 (Framework and Pro) was released on April 21st, 2022.
Automatic Upgrade Instructions
Unified Changelog for s2Member & s2Member Pro v220421
(Framework & Pro) Enhancement: Improved PHP compatibility to 8.1.
(Framework) UI Fix:
More Updateslink fixed.
Upgrading to the Latest Version
s2Member Framework users should receive an update notification from within their WordPress Dashboard (WordPress Dashboard → Updates).
s2Member Pro users: Please update the Framework first. You will then be prompted for your s2Member.com username and license key so that you can update the Pro module. If you have trouble, you can follow the manual installation instructions.
The s2Member Pro Add-on requires that you have a matching version of the s2Member Framework to go with it. Therefore, if you update your copy of the s2Member Framework without also updating the s2Member Pro Add-on, your copy of the s2Member Pro Add-on (now outdated) will refuse to load, disabling the Pro features. Just update the Pro add-on to match the Framework's and Pro will reactivate.