This is not a minor visual glitch or a negligible beta bug; this is a catastrophic telecom and safety failure. In iOS 27 Developer Beta, attempting to activate Wi-Fi Calling for US carriers (like RedPocket, Mint, T-Mobile, etc.) that require an E911 address registration completely hard-crashes the Settings app. You cannot activate Wi-Fi Calling, you cannot register your emergency address, and your cellular service is effectively crippled. As an SRE, I pulled the Console logs and traced the crash. It is absolutely unacceptable that Apple is still relying on the ancient, long-deprecated ⁠UIWebBrowserView⁠ inside ⁠TPSCloudCallingWebViewController⁠ for a critical emergency service configuration page. The Settings app is dying from a dual-concurrency crash caused by aggressive iOS 27 refactoring colliding with this legacy web container: The Apple Intelligence / TextInputUI Collision: On page load, the new text prediction engine blindly scans the legacy web input fields and throws a fatal exception: ⁠-[UIThreadSafeNode _smartReplyUpdateInProgress]: unrecognized selector sent to instance⁠. The old web node simply doesn't support the new Smart Reply APIs. The WebKit Thread Violation: This input system failure (⁠RTIInputSystemClient⁠ invalidation) cascades into a complete WebKit thread deadlock. The engine attempts to parse the carrier's CSS and throws a fatal UIKit assertion: ⁠Modifying properties of a view's layer off the main thread is not allowed⁠. The OS instantly sends a ⁠SIGABRT⁠ to ⁠com.apple.Preferences⁠. I have tried every possible workaround: Disabling JavaScript, removing 3rd-party/foreign keyboards, turning off predictive text, and even using MITM proxies to strip the CSS from the carrier's gateway. Nothing works. The crash happens instantly on load because the TextInputUI injection and the background-thread layer mutation are hardcoded into the OS framework. It is utterly absurd that a broken Smart Reply UI prediction path can block a user from registering an emergency 911 address and activating their phone service. Apple, you need to fix this immediately. Either rewrite ⁠TPSCloudCallingWebViewController⁠ to use a modern ⁠WKWebView⁠, or patch ⁠TextInputUI⁠ to gracefully handle legacy ⁠UIThreadSafeNode⁠ instances. Do not ship another beta with a broken carrier service page.