If it was updated, it was done automatically without my knowledge. Can I just revert to the previous version to regain root?You probably lost root because you updated the Superuser app. The OP says NOT to update it because it will break root. Onthe other hand, S-Health is tied to Knox (not root). The latest version of S-Health checks for an intact Knox. Since this ROM has Knox removed, it will not work with the updated version. Once the knox check is done, it will fail to load the app.