I've encountered this exact same problem. I follow this guide to a tee: https://developer.apple.com/documentation/xcode/configuring-your-app-to-use-alternate-app-icons And yet I am consistently hit with: Failed: Error Domain=NSPOSIXErrorDomain Code=35 "Resource temporarily unavailable" UserInfo={_LSFile=LSIconAlertManager.m, _LSLine=113, _LSFunction=-[LSIconAlertManager iconChangeAlertTokenForIdentity:error:]} My app targets iPads and iPhones, has a minimum version for iOS of 18, and I am not using a simulator, I am running on my own device (iPhone 17 on iOS 26.2). This has been driving me insane. The example project Apple provides works, so I cannot see what possibly could be different.