We're experiencing the same issue with our app during passkey registration. I redacted the actual domain and app information below. ==== iOS 16.0.2 (app built with Xcode 14.2) Passkey registration worked correctly with the following setup iOS 16.0.2 (app built with Xcode 14.2). App association file in DOMAIN_URL has the content: { "webcredentials":{ "apps":["APP_ID.APP_BUNDLE_ID"] } } Associated domains in the project and developer mode is webcredentials:DOMAIN_URL?mode=developer On my iPhone, under Settings >> Developer, I have "Associated Domains Development" toggled on ==== iOS upgraded to 16.4.1 (re-ran the app built with Xcode 14.2) After the upgrade I ran the same app and AuthenticationServices started showing this error in the logs. ASAuthorizationController credential request failed with error: Error Domain=com.apple.AuthenticationServices.AuthorizationError Code=1004 "(null)" ==== Rebuilt the app for iOS 16.4.1 using Xcode 14.3 After rebuilding the app with Xcode 14.3 the error reason is Error Domain=com.apple.AuthenticationServices.AuthorizationError Code=1004 "Application with identifier APP_ID.APP_BUNDLE_ID is not associated with domain DOMAIN_URL" UserInfo={NSLocalizedFailureReason=Application with identifier APP_ID.APP_BUNDLE_ID is not associated with domain DOMAIN_URL} I wonder if any issues were introduced to the AuthenticationServices or to the debug options for Associated Domains.