Game Center App (for iOS 9 and below) Game Center app allows users to play and challenge friends when playing online multiplayer and social gaming network games. Additionally, Game Center even shares multiplayer functionality between the Mac and iDevice versions of the app. The Game Center App also keeps track of various game achievements. Sep 11, 2019  GameCenter not Linking GameKit (OSX) - SOLVED. Discussion in 'iOS and tvOS' started by MrEsquire, Nov 5, 2015. Invalid Signature - The main app bundle MyGame at path MyGame.app has following signing error(s): invalid signature. You can see I successfully uploaded to Mac both with StoreKit and Game Center without issues.

Create a Game Center profile

1. On your iPhone, iPad, or iPod touch, open Settings. Scroll to Game Center, then tap it.
2. If Game Center isn’t on, turn it on, then sign in with your Apple ID.*
3. Tap the Nickname field to enter a name that your friends will see when you play games together. If you can’t think of a name, you can choose one of the randomly generated suggestions.
4. To personalize the picture that shows with your nickname, tap Edit in the circle at the top of the page. From here, you can create a Memoji, use an existing one, or customize how your nickname's initials appear.

Use Game Center with iCloud

You can access your game saves, high scores, and friends on all of your devices by using Game Center and iCloud. This is on by default.

Learn how to access your game saves across all of your devices.

* If you see a nickname or other information already set up, you might already have a Game Center profile. Check Settings > [your name] to verify that you’re signed in with your Apple ID.

Manage users in Game Center

Add friends

1. On your iPhone, iPad, or iPod touch, open Settings. Scroll to Game Center, then tap it.
2. Tap Add Friends.
3. Enter the phone number of the person that you want to invite to be friends in Game Center, or you can tap to invite one of your contacts. Once that person accepts the request through the Messages app, you'll be able to see them on your list of friends.

Remove friends or report Game Center users

1. On your iPhone, iPad, or iPod touch, open Settings. Scroll to Game Center, then tap it.
2. Tap Friends to see a list of users who you're friends with and users who you've recently played with.
3. Swipe left over the user's name to reveal more options. Tap Remove to stop being friends with someone in Game Center. Tap Report and follow the onscreen instructions to report a profile for cheating, inappropriate content, or another problem.
   

Learn more

• Subscribe to Apple Arcade to find and play Apple Arcade games with friends.
• On an Apple TV, you can sign in and sign out of a Game Center account in Settings > Users and Accounts > Game Center.
• To accept a friend request, the recipient must click the link in the text message on their iOS 13 or iPadOS 13 device. They can’t accept friend requests on older operating systems, computers, or Android devices.

When you first set up Messages on your Mac, you're asked to sign in to your iMessage account with your Apple ID. Messages then automatically attempts to sign in every time you open it. Signing in to FaceTime is similar. If either app doesn't sign in successfully, try these solutions.

Check your Internet connection

Make sure that your Mac is connected to the Internet. You should be able to load web pages or receive email, for example.

Check for a service outage

Check the Apple System Status page for a temporary outage affecting iMessage or FaceTime.

Check your Date & Time settings

• Choose Apple menu () > System Preferences, then click Date & Time. Make sure that the date, time, and time zone are correct.
• If the ”Set date and time automatically” checkbox is selected, deselect it and select it again. (If the checkbox is dimmed, click and enter your administrator password.)

Make sure that your software is up to date

Learn how to update your Mac software. Software updates can improve the stability, compatibility, and security of your Mac, and might also resolve the issue.

Check your Apple ID

To make sure that your Apple ID and password are correct, go to the Apple ID account page and sign in with the same Apple ID that you're using with Messages and FaceTime. If that works, open the app and take these steps:

• Messages: Choose Messages > Preferences, then click Accounts. Select your iMessage account, then click Sign Out. Now sign in again with the same Apple ID you used on the Apple ID account page.
• FaceTime: Choose FaceTime > Preferences. In the Settings tab, click Sign Out. Then sign in again with the same Apple ID you used on the Apple ID account page.

Reset NVRAM

In case the issue is related to any of the settings stored in NVRAM, reset NVRAM on your Mac.

Check for third-party software

If you installed firewall, security, VPN, or other third-party networking software, make sure that the software isn't blocking any of the network ports used by iMessage and FaceTime. If necessary, disable the software and then try using your iMessage account or FaceTime again.

Learn more

Game Center Login Error Mac Pro

Learn what to do if you have other FaceTime issues.

Game Center Login Error Machine

FaceTime is not available in all countries or regions.