Yesterday, proving it is far from infallible when it comes to both hardware design and software development, Apple released a faulty version of iOS 8.0.1. For many iPhone 6 and iPhone 6 Plus users, updating to iOS 8.0.1 completely killed cellular connectivity and TouchID functionality. To restore cellular (and mobile data) connectivity, the only solution is to downgrade back to iOS 8 and await a future 8.0.2 update from Apple, which is due 'in the next few days.'