In OS 8 we kept the Classic Session as default with the option to try a Secure Session. Since then we’ve released updates fixing issues, app developers have updated, and hardware makers have fixed issues in their drivers. The Secure Session now provides a better experience for most people and supports a broader range of modern hardware
In OS 8.1, the Secure Session is now the default session, with the option to fall back to the Classic Session if you still need it