Hi — we’re testing our app on iOS 26 and ran into strange behavior with GKLocalPlayer.local.authenticateHandler.
GKLocalPlayer.local.authenticateHandler = { [weak self] viewController, error in
// additional code
}
What happens:
When we assign authenticateHandler on iOS 26 and the user is not signed in to Game Center, the system shows a full-screen Game Center overlay asking the user to sign in.
If the user taps Cancel, nothing further happens — the closure is not invoked again, so we don’t receive an error or any callback. The app never learns whether the auth was cancelled or failed.
In previous iOS versions the closure was called (with viewController / error as appropriate) and the flow worked as expected.
What we tried:
Verified authenticateHandler is being set.
Checked GKLocalPlayer.local.isAuthenticated after the overlay dismisses — it’s unchanged.
Observed system logs: a com.apple.GameOverlayUI scene is created and later removed (so the auth overlay is shown by the system).
Confirmed the same code works on earlier iOS versions. :thinking:
Question:
Has anyone seen authenticateHandler not being invoked on iOS 26 when the Game Center auth overlay is presented? Could this be a behavioral change in iOS 26 (overlay runs in a separate system process), or a bug? Any suggested workarounds to reliably detect that the user cancelled the sign-in (for example: listening for willResignActive / didBecomeActive, watching for a system overlay, or saving/presenting the viewController manually)?
Thanks in advance for any advice — we’d appreciate pointers or suggested diagnostics ?
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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
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!
I just upgraded my macOS, Xcode and Simulator all to the newest beta version 26.
Then I found two issues when building my app with Xcode 26 and running it on simulator 26.
The game center access point no longer shows up in the app. This is how it's configured in the past. And it still works on simulator 18.4
func authenticatePlayer() {
GKAccessPoint.shared.location = .topTrailing
self.localPlayer.authenticateHandler = { viewController, error in
if let viewController = viewController {
// can present Game Center login screen
} else if self.localPlayer.isAuthenticated {
// game can be started
} else {
// user didn't log in, continue the game without game center
}
}
}
After game ended, the leaderboard won't load. This is how it's implemented in the past. It's still working in simulator 18.4
struct GameCenterView: UIViewControllerRepresentable {
@Environment(\.presentationMode) var presentationMode
...
func makeUIViewController(context: Context) -> GKGameCenterViewController {
let viewController = GKGameCenterViewController(
leaderboardID: getLeaderBoardID(with: leaderBoardGameMode),
playerScope: .global,
timeScope: .allTime
)
viewController.gameCenterDelegate = context.coordinator
return viewController
}
func updateUIViewController(_ uiViewController: GKGameCenterViewController, context: Context) {}
func makeCoordinator() -> Coordinator {
Coordinator(self)
}
class Coordinator: NSObject, GKGameCenterControllerDelegate {
let parent: GameCenterView
init(_ parent: GameCenterView) {
self.parent = parent
}
func gameCenterViewControllerDidFinish(_ gameCenterViewController: GKGameCenterViewController) {
parent.presentationMode.wrappedValue.dismiss()
}
}
}
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...
I am currently working on a game that involves earning achievements, which I am using the Apple Unity Plug-Ins to display. I have found that occasionally opening the Game Center Dashboard the last achievement earned will not be displayed until the game is closed and reopened. I am using GKAccessPoint.Shared.Trigger to display the Achievements screen, which occasionally seems to open a cached version of the dashboard. I've found that it seems to consistently happen when earning multiple achievements within one minute, but this is not always the case. Does anybody have any experience with something like this in the past?
Added achievements to my approved app. Added them for the next release version, which I am running in simulator. When I look at the Achievements page, I can see that there are 17 Achievements available (correct), but they all show as hidden, despite checking the "No" box in App Store Connect.
Topic:
Graphics & Games
SubTopic:
GameKit
When running my game in the Unity Editor on Windows platform I get an error:
DllNotFoundException: GameKitWrapper assembly:<unknown assembly> type:<unknown type> member:(null)
Apple.GameKit.DefaultNSErrorHandler.Init () (at ./Library/PackageCache/com.apple.unityplugin.gamekit@0abcad546f73/Source/DefaultHandlers.cs:35)
This is because GameKitWrapper dynamically linked library is not available under Windows platform.
Besides, "Apple Build Settings" are declared under UNITY_EDITOR_OSX and also not available under Windows platform.
Does anyone managed to solve this?
Hey all — I’ve been building out my first set of Game Center Achievements for a game I’m working on, and I’ve run into something odd with the image quality.
The specs say to upload icons at 512x512 or 1024x1024@2x. I’ve been uploading 1024x1024 PNGs (without explicitly naming them “@2x” since there’s only one upload slot), assuming that Game Center would just handle the scaling automatically — kind of like how a lot of things are getting more streamlined across platforms lately.
But in testing, the icons are showing up a bit blurry, especially in the Game Center interface. It’s not horrible, but it’s definitely softer than I expected — more like low-res than Retina.
All my test devices (outside the Simulator) are running iOS 26, so I’m also wondering if this might be a beta-related display bug?
Has anyone else run into this? Curious if I’m missing a best practice here, or if I really do need to ensure I’m uploading it with the @2x suffix, or maybe something else entirely?
Thanks!
Issues building Unity plug-in project: Cannot locate native library Apple.Core/Apple.GameKit for iOS
I'm having issues getting a well built package from the Apple Unity Plug-in project.
When building the my game project in Unity the following error is printed to the console:
Apple.Core.AppleNativeLibraryUtility] Cannot locate a Debug or Release Apple.Core native library for iOS.
Please ensure that the build invocation (build.py, xcodebuild, or Xcode) compiled cleanly and that the build was configured to support Debug on iOS.
As far as I can tell the build did compile cleanly, but I might be missing something.
If anyone can see what I'm doing wrong or has any insight it would be greatly appreciated.
Setup is the following:
macOS Tahoe 26 Beta
Xcode-beta Version 26.0 beta 3 (17A5276g)
Unity Plug-in branch: 2025-beta1
Unity game project version: 2022.3.60f
M1 Macbook Pro
The built packages have been imported into the game project through the Unity Package Manager using the tarball option pointing to the built packages from the Unity Plug-in project.
The Unity Plug-in project has been built using the build.py file with the following:
python3 build.py -m iOS iPhoneSimulator -p Core GameKit CoreHaptics GameController -k all
The output is available in the attached file.
build-output.txt
Here's an image of the NativeLibraries~ folder inside the built Apple.Core package.
Hello,
**I'm Using **
Unity 6 LTS
Unity Apple GameKit + Core plugins
Turn-based matchmaking interface w/ 2 players max
App Store Connect API for rule-based matchmaking
I have already
enabled game center in app store connect (I think)
authenticated players and matched via friend request
I am stuck
Using queues to match players automatically
I'm working on a rule-based matchmaking system which aims to place two players against each other into a GKTurnBasedMatch. I have a simple Unity Project that correctly authenticates a user and proceeds to send a matchmaking request. The matchmaking script utilizes the Unity plugins' GKTurnBasedMatchmakerViewController.Request(...) request function with a GKMatchRequest.Init() request configured with a QueueName equal to the App Store Connect API Queue I created.
The queue I created is also linked to a ruleset with a very basic rule that checks if the properties contains a key called 'preference' that contains a string value for what side the player wants to play for this match. If during the matchmaking, the preferences between players are different, then the match is made and both players should join the match; each player gets to play the side they have chosen. I have my rule expression designed to just check if the preferences are not equal:
requests[0].properties.faction_preference != requests[1].properties.faction_preference
When I launch the game with two physical iPads and begin the matchmaking request, each player is immediately presented with two options:
Invite a friend, or
Start game
The Problem: Inviting a friend works to get two players into a game, but queue seems to not matter, and clicking start game will just put the current player into its own match (no one joins).
The Question: How do I get queue based matchmaking to work in Unity for a Turn-based match with only two players who are able to select the enemy side they want to play dictated by a rule that compares enemy play-side preferences?
Resources I've used:
Apple Unity GameKit Plugin: https://github.com/apple/unityplugins
Matchmaking: https://developer.apple.com/documentation/gamekit/matchmaking-rules
Multiplayer rulesets: https://developer.apple.com/documentation/gamekit/finding-players-using-matchmaking-rules
Topic:
Graphics & Games
SubTopic:
GameKit
Tags:
GameKit
Graphics and Games
App Store Connect
Apple Unity Plug-Ins
Hi,
Since iOS 26 introduced the new Games app, I’ve noticed a problem when using a Nintendo Switch Pro Controller in wired USB-C mode, and also with third-party controllers that emulate it (like the GameSir X5 Lite).
In the Games app interface, only the L/R buttons respond, but the D-Pad and analog sticks don’t work at all. Once inside actual games, the controller works fine — the issue only affects the Games app UI.
What I’ve tested so far:
Xbox / PlayStation controllers → work fine in both wired and Bluetooth, including inside the Games app.
Switch Pro Controller (Bluetooth) → works fine, including in the Games app.
Switch Pro Controller (wired) → same issue as the X5 Lite, D-Pad and sticks don’t work in the Games app.
This makes it hard to use the new Games app launcher with these controllers, even though they work perfectly once a game is launched.
My question: is this an iOS bug (Apple needs to add proper support for wired Switch Pro controllers in the Games app), or something that Nintendo / GameSir would need to address?
Thanks in advance to anyone who can confirm this or provide more info.
We have a released game in the App Store with Game Center Challenges. The challenges were working well in testing of the final version before the Game Center challenges went live. After release the activity that should take the player to the challenge in game results in this printout and we do not get informed by GKGameActivityListener of the activity happening in our code as we did before the Game Center challenges went live.
“Invalid game activity definition.
Failed to kick activity notification to GameKit. Error: Error Domain=GKErrorDomain Code=17 "(null)"”
Also, Game Center reports that the are no challenges in GKChallengeDefinition.all even though there are ongoing challenges.
The leaderboard results do get reported to Game Center though and show up as challenge entries in the Games app.
At the moment we are trying to figure out if this is a problem on our end or a Game Center server issue.
Topic:
Graphics & Games
SubTopic:
GameKit
Hello -
Upon enabling debug mode for GameKit configuration for my iOS app, I do not see any devices (my iPhone or simulators) in the device list within the "Manage Game Progress" debug tool. I only see my Mac as a device. Is there any trick to this or a way to add devices to this list?
Thank you
I typically read an extended gamepad capture() and get all state. But PSVR2 controllers seem to report nothing. So the stick and other buttons don't do anything in a built app. They register as left/right controllers. This on vOS 26, Xcode 26, etc.
They work correctly in the main icon view, although they don't honor inverted vertical and horiztonal scrolling. Both of the default scrolls just feel wrong. When I move left I'm want to scroll level not right. Same for up/down.
Attempting to bring up the access point yields the following error log:
[GameCenterOverlayService] Failed to create GameOverlayUI Dashboard Remote Proxy
[GameCenterOverlayService] Could not create endpoint for service name: com.apple.GameOverlayUI.dashboard-service
[GameCenterOverlayService] Failed to create GameOverlayUI Dashboard Remote Proxy
[GameCenterOverlayService] Could not create endpoint for service name: com.apple.GameOverlayUI.dashboard-service
[GameCenterOverlayService] Failed to create GameOverlayUI Dashboard Remote Proxy
[GameCenterOverlayService] Failed to create GameOverlayUI Dashboard Remote Proxy
The same code (which is a single line setting 'active' to true) works on physical devices and on the simulator in iOS 18.6
I haven't been able to find any mention of this issue online. Any suggestions or help greatly appreciated.
Hi everyone
I'm experiencing an issue with iPadOS 26 regarding multi-touch gesture detection. When performing a quick four-finger gesture (tap and swipe), the system often fails to recognize the input. This especially affects multi-touch gestures, such as rhythm games with difficult levels.
Steps to Reproduce:
Place four fingers on the screen.
Perform a quick tap or a quick horizontal swipe (like the one used to switch apps).
Observe whether the gesture is ignored or detected inconsistently.
Expected Behavior:
4-finger multitouch gestures should be recognized regardless of gesture speed, just like previous iPadOS versions.
Actual Behavior:
Gestures fail to be detected when executed quickly—same gestures still work, and miss notes in rhythm games.
You can check out my posts on Twitter/x and Facebook: [https://x.com/kokona_fwa/status/1978131164104728949?s=61]
Facebook: [https://m.facebook.com/groups/idipad/permalink/24438964899058806/?]
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, I’m creating a game and I’m just wondering if I can integrate GCVirtualController in my SwiftUI app.
Hi. The earliest version of MacOS that Unity supports is 10.13. However, it seems that running a game using Unity Plugins on 10.13 causes DLL loading exceptions whenever you try to access part of the GameKit API. The errors look like this:
Fallback handler could not load library /Users/love/Desktop/REDACTED/Contents/Frameworks/MonoEmbedRuntime/osx/GameKitWrapper
Fallback handler could not load library /Users/love/Desktop/REDACTED/Contents/Frameworks/MonoEmbedRuntime/osx/libGameKitWrapper.dylib
Fallback handler could not load library /Users/love/Desktop/REDACTED/Contents/Frameworks/MonoEmbedRuntime/osx/libGameKitWrapper.dylib
Fallback handler could not load library /Users/love/Desktop/REDACTED/Contents/Frameworks/MonoEmbedRuntime/osx/libGameKitWrapper.so
Fallback handler could not load library /Users/love/Desktop/REDACTED/Contents/Frameworks/MonoEmbedRuntime/osx/libGameKitWrapper.bundle
DllNotFoundException: GameKitWrapper assembly:<unknown assembly> type:<unknown type> member:(null)
at (wrapper managed-to-native) Apple.GameKit.DefaultNSErrorHandler+Interop.DefaultNSErrorHandler_Set(Apple.Core.Runtime.NSExceptionCallback)
at Apple.GameKit.DefaultNSErrorHandler.Init () [0x00001] in ./Library/PackageCache/com.apple.unityplugin.gamekit@e3d4ad5a2c8e/Source/DefaultHandlers.cs:35
(Filename: ./Library/PackageCache/com.apple.unityplugin.gamekit@e3d4ad5a2c8e/Source/DefaultHandlers.cs Line: 35)
Fallback handler could not load library /Users/love/Desktop/REDACTED/Contents/Frameworks/MonoEmbedRuntime/osx/GameKitWrapper
Fallback handler could not load library /Users/love/Desktop/REDACTED/Contents/Frameworks/MonoEmbedRuntime/osx/libGameKitWrapper.dylib
Fallback handler could not load library /Users/love/Desktop/REDACTED/Contents/Frameworks/MonoEmbedRuntime/osx/libGameKitWrapper.dylib
Fallback handler could not load library /Users/love/Desktop/REDACTED/Contents/Frameworks/MonoEmbedRuntime/osx/libGameKitWrapper.so
Fallback handler could not load library /Users/love/Desktop/REDACTED/Contents/Frameworks/MonoEmbedRuntime/osx/libGameKitWrapper.bundle
DllNotFoundException: GameKitWrapper assembly:<unknown assembly> type:<unknown type> member:(null)
at (wrapper managed-to-native) Apple.GameKit.DefaultNSExceptionHandler+Interop.DefaultNSExceptionHandler_Set(Apple.Core.Runtime.NSExceptionCallback)
at Apple.GameKit.DefaultNSExceptionHandler.Init () [0x00001] in ./Library/PackageCache/com.apple.unityplugin.gamekit@e3d4ad5a2c8e/Source/DefaultHandlers.cs:14
These errors do not appear on 10.15 or later, which is why I am assuming it's a problem with this particular version of MacOS. Have not been able to test 10.14 so not sure how it handles there.
So, here is my question - what is the earliest version of MacOS that the Apple Unity plugins support? It's not documented anywhere on the GitHub page.
// Love