In my SceneKit game I'm able to connect two players with GKMatchmakerViewController. Now I want to support the scenario where one of them disconnects and wants to reconnect. I tried to do this with this code: nonisolated public func match(_ match: GKMatch, player: GKPlayer, didChange state: GKPlayerConnectionState) { Task { @MainActor in switch state { case .connected: break case .disconnected, .unknown: let matchRequest = GKMatchRequest() matchRequest.recipients = [player] do { try await GKMatchmaker.shared().addPlayers(to: match, matchRequest: matchRequest) } catch { } @unknown default: break } } } nonisolated public func player(_ player: GKPlayer, didAccept invite: GKInvite) { guard let viewController = GKMatchmakerViewController(invite: invite) else { return } viewController.matchmakerDelegate = self present(viewController) } But after presenting the view controller with GKMatchmakerViewController(invite:), nothing else happens. I would expect matchmakerViewController(_:didFind:) to be called, or how would I get an instance of GKMatch? Here is the code I use to reproduce the issue, and below the reproduction steps. Code Run the attached project on an iPad and a Mac simultaneously. On both devices, tap the ship to connect to GameCenter. Create an automatched match by tapping the rightmost icon on both devices. When the two devices are matched, on iPad close the dialog and tap on the ship to disconnect from GameCenter. Wait some time until the Mac detects the disconnect and automatically sends an invitation to join again. When the notification arrives on the iPad, tap it, then tap the ship to connect to GameCenter again. The iPad receives the call player(_:didAccept:), but nothing else, so there’s no way to get a GKMatch instance again.

I have an AR game using ARKit with SceneKit that works just fine in iOS 17. In the iOS 18 betas, the AR background image shows black instead of showing the real world. As a result there's no tracking and obviously the whole game is useless. I narrowed down the issue to showing the Game Center Access Point. My app has ViewController 1 (VC1) showing the main menu and that's where I want to show the GC Access Point. From there you open VC2 which shows a list of levels. Selecting any level will open VC3 which has the ARScene. Following is the code I use to start Game Center in VC1: GKLocalPlayer.local.authenticateHandler = { gcAuthVC, error in let isGameCenterReady = (gcAuthVC == nil) && (error == nil) if let viewController = gcAuthVC { self.present (viewController, animated: true, completion: nil) } if error != nil { print(error?.localizedDescription ?? "") } if isGameCenterReady { GKAccessPoint.shared.location = .topLeading GKAccessPoint.shared.showHighlights = true GKAccessPoint.shared.isActive = true } } When switching to VC2 I run GKAccessPoint.shared.isActive = false so that the Access Point will no longer show in any of the following VCs. I tried running it in VC1, VC2, and again in VC3 - it doesn't change anything. Once I reach VC3, the background is black. If in VC1 I don't run GKAccessPoint.shared.isActive = true, so I don't activate the access point, the behavior is as follows: If I wait until after the Game Center login animation completes and closes on its own and then I proceed to VC2 and VC3, the camera image will show correctly If I quickly move to VC2 before the Game Center login animation has completed, so my code will close it by setting active = false, and then I continue to VC3, I will see the black background problem. So it does look like activating the access point and then de-activating it causes the issue. BTW, if I activate the access point and leave it on in all VCs, the same black background issue persists. Other than that, when I'm in VC3 with the black background and I switch to another app (so my game moves to the background), when it returns to the foreground, the camera suddenly shows the real world correctly! I tried to manually reset the AR session by pausing and restarting it, but that didn't change anything. Also, when I check with the debugger, it looks like when the app comes back to the foreground it also doesn't run the session start code. But something does seem to reset itself so I wonder what that is. Maybe I could trigger the same manually in my cdoe??? I repeat that everything works just fine in iOS 17 and below. This problem only started with the iOS 18 beta (currently on beta 5, but it started in some of the previous betas as well). So could this be a bug in iOS 18? As a workaround I could check the iOS version and if it's iOS18 not activate the access point, hoping that the user will not jump to VC2 too quickly, and show my own button which will open Game Center. But I'd rather give the users the full experience with their own avatar and the highlights showing up. Plus, certainly some users will move quickly to VC2 and that will be an awful experience. Any help would be greatly appreciated. Thanks!

Hey, i have created a game in unity with the apple core and apple gamekit plugins present. I setup 5 leaderboards on the app store connect. I made a unity build and did the whole testflight build loop to test everything. When i open my gamecenter panel via the button i see my leaderboards but they show as MISSING TITLE which is weird because i have for sure set them up correctly they have a leaderboard reference name and leaderboard id as well. When debugging i can see that when i call my submit score function it gets submitted with no error but then i also dont see the score appear anywhere . Keep in mind the leaderboards are not live and are being tested on testflight first

Hi All! I'm being asked to migrate an app which utilizes iCloud KVS (Key Value Storage). This ability is a new-ish feature, and the documentation about this is sparse [1]. Honestly, the entire documentation about the new iCloud transfer functionality seems to be missing. Same with Game Center / GameKit. While the docs say that it should work, I'd like to understand the process in more detail. Has anyone migrated an iCloud KVS app? What happens after the transfer goes through, but before the first release? Do I need to do anything special? I see that the Entitlements file has the TeamID in the Key Value store - is that fine? <key>com.apple.developer.ubiquity-kvstore-identifier</key> <string>$(TeamIdentifierPrefix)$(CFBundleIdentifier)</string> Can someone please share their experience? Thank you! [1] https://developer.apple.com/help/app-store-connect/transfer-an-app/overview-of-app-transfer

Hi all I have two mystic issues with saving and fetching data to and from iCloud. Both repro only after first launch of an app. 1. [GKLocalPlayer fetchSavedGamesWithCompletionHandler:] After first attempt I can see 0 saved games (but i know that there is at least one saved game) and there is no any error. In case if I try fetch one more time (without any additional actions) even immediately after first attempt I receive saved games correctly (not 0) 2. [GKLocalPlayer saveGameData: withName: completionHandler:] After first attempt I can see error The requested operation could not be completed because local player has not been authenticated. In case if I try save one more time (without any additional actions) even immediately after first attempt I can save data successfully without any error I found the same issue in StackOverflow, but there are no fixes...

Hello! Bare with me here, as there is a lot to explain! I am working on implementing a Game Center high score leaderboard into my game. I have looked around for examples of how to properly implement this code, but have come up short on finding much material. Therefore, I have tried implementing it myself based off information I found on apples documentation. Long story short, I am getting success printed when I update my score, but no scores are actually being posted (or at-least no scores are showing up on the Game Center leaderboard when opened). Before I show the code, one thing I have questioned is the fact that this game is still in development. In AppStoreConnect, the status of the leaderboard is "Not Live". Does this affect scores being posted? Onto the code. I have created a GameCenter class which handles getting the leaderboards and posting scores to a specific leaderboard. I will post the code in whole, and will discuss below what is happening. PLEASE VIEW ATTACHED TEXT TO SEE THE GAMECENTER CLASS! GameCenter class - https://developer.apple.com/forums/content/attachment/0dd6dca8-8131-44c8-b928-77b3578bd970 In a different GameScene, once the game is over, I request to post a new high score to Game Center with this line of code: GameCenter.shared.submitScore(id: GameCenterLeaderboards.HighScore.rawValue) Now onto the logic of my code. For the longest time I struggled to figure out how to submit a score. I figured out that in Xcode 12, they deprecated a lot of functions that previously worked for me. Not is seems that we have to load all leaderboards (or the ones we want). That is the purpose behind the leaderboards private variable in the Game Center class. On the start up of the app, I call authenticate player. Once this callback is reached, I call loadLeaderboards which will load the leaderboards for each string id in an enum that I have elsewhere. Each of these leaderboards will be created as a Leaderboard object, and saved in the private leaderboard array. This is so I have access to these leaderboards later when I want to submit a score. Once the game is over, I am calling submitScore with the leaderboard id I want to post to. Right now, I only have a high score, but in the future I may add a parameter to this with the value so it works for other leaderboards as well. Therefore, no value is passed in since I am pulling from local storage which holds the high score. submitScore will get the leaderboard from the private leaderboard array that has the same id as the one passed in. Once I get the correct leaderboard, I submit a score to that leaderboard. Once the callback is hit, I receive the output "Successfully submitted score to leaderboard". This looks promising, except for the fact that no score is actually posted. At startup, I am calling updatePlayerHighScore, which is not complete - but for the purpose of my point, retrieves the high score of the player from the leaderboard and is printing it out to the console. It is printing out (0), meaning that no score was posted. The last thing I have questions about is the context when submitting a score. According to the documentation, this seems to just be metadata that GameCenter does not care about, but rather something the developer can use. Therefore, I think I can cross this off as causing the problem. I believe I implemented this correctly, but for some reason, nothing is posting to the leaderboard. This was ALOT, but I wanted to make sure I got all my thoughts down. Any help on why this is NOT posting would be awesome! Thanks so much! Mark