@DTS Engineer Ok, I followed your steps and discovered something interesting 🤓 Since my project is quite large, I initially decided to move and run the test code directly in the AppDelegate’s application(_:didFinishLaunchingWithOptions:) method. And it works! Even the UIApplication.shared.setAlternateIconName() method works as well. final class AppDelegate: UIResponder, UIApplicationDelegate { func application( _ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]? ) -> Bool { Task { _ = try! await URLSession.shared.allTasks try! await UIApplication.shared.setAlternateIconName(...) } } } Another unexplained curious thing I noticed is that after making these API calls in AppDelegate, my original code starts to work 😳 I'll provide some more information about my project, in case it helps. My project uses a modular architecture, and I use Tuist to generate the .xcodeproj and .xcworkspace files. The code that's causing the crash is located in a SwiftPM package. Additionally, the allTasks code is in one package, while setAlternateIconName() is in another. Tuist generates subprojects with statically linked frameworks from these SwiftPM packages.

@DTS Engineer thank you for your prompt response 🙏 I have macOS 15.5 and Xcode 16.4. I repeated your steps: Created a new project; Implemented the same button with the same action. Everything works fine. Moreover, all of the APIs listed above work well in other projects. It’s definitely something specific to my project. Unfortunately, I have no idea what’s causing the issue or what I need to do next.

After upgrading to Xcode 16, I have experienced some issues with the compilation time of my project. I noticed that a new step has been added called "Scan dependencies of", which was not present in Xcode 15. Additionally, there is a new CompileAssetCatalogVariant step. The ValidateEmbeddedBinary step has started to take ~15 seconds, compared to about 5 seconds in Xcode 15. I would appreciate any recommendations on what I can do with that information 🙏