Hi @b_rare, your message helped knock my brain into gear when I was really confused, thank you... in case this helps you or any other lost devs... I was seeing this same Task or actor isolated value cannot be sent warning on Xcode 16.1 when I tried to do something very similar: Unable to move from nonisolated to @MainActor with a Task extension ViewController: MKLocalSearchCompleterDelegate { nonisolated func completerDidUpdateResults(_ completer: MKLocalSearchCompleter) { Task { @MainActor in searchBar.searchTextField.searchSuggestions = completer.results.map { result in UISearchSuggestionItem(localizedSuggestion: result.title, localizedDescription: result.description) } } } Fix I have made the errors go away by mapping the results properties to a tuple with just the String values I needed: extension ViewController: MKLocalSearchCompleterDelegate { nonisolated func completerDidUpdateResults(_ completer: MKLocalSearchCompleter) { let results = completer.results.map { result in (result.title, result.description) } Task { @MainActor in searchBar.searchTextField.searchSuggestions = results.map { result in UISearchSuggestionItem(localizedSuggestion: result.0, localizedDescription: result.1) } } } Why it works My understanding is that since completer: MKLocalSearchCompleter and completer.results: [MKLocalSearchCompletion] are both classes (reference types) and not final, they are therefore NOT Sendable. Strings, however, are value types, so they are Sendable and can be passed between isolation domains.

I had this issue when I set the image icons using JPEGs instead of PNGs. I swapped the images over, no more issues.

I had this issue when I set the image icons using JPEGs instead of PNGs. I swapped the images over, no more issues.