Select Target then in "General" section "Frameworks, Libraries, and Embedded Content press + and search AudioToolBox, and in file import AudioToolBox

When adding @MainActor on whole viewModel class then those messages disappearing but if those messages still are and if that @MainActor no need, then how much important those messages?

If you write code like that in function and then call the function? private func disableIdleTimer() { #if os(iOS) UIApplication.shared.isIdleTimerDisabled = true #elseif os(macOS) NSApplication.shared.isIdleTimerDisabled = true #endif } private func enableIdleTimer() { #if os(iOS) UIApplication.shared.isIdleTimerDisabled = false #elseif os(macOS) NSApplication.shared.isIdleTimerDisabled = false #endif } }

For solution like that need update DeviceSupport file in /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/DeviceSupport DeviceSupport file possible download from https://github.com/filsv/iOSDeviceSupport#readme but for 15.8 no file yet.

In Book Develop in Swift Exploration 11 page, I think in every book is "Download student material"

When you also lose files and see post which "Posted 4 years ago" with zero comments on it... sad.