I'm using the Apple Unity Plugins to use Game Center to authenticate Playfab accounts for my game and when I test this on testflight, everything works fine for me and the people I've tested with, however, when I send the build to review, they are getting GameKitException 37 which states "This game is not listed in a marketplace that supports Game Center" and upon further research I found this page https://developer.apple.com/documentation/gamekit/gkerror/code/appunlisted which I'm assuming is the same thing.
This seems to suggest that I need my app to be listed on the App Store which is strange because this has created a what comes first, the chicken or the egg problem. I need to pass review to get the game listed in the App Store and they can't test the game because accounts cannot be authenticated with Game Center which apparently needs to be listed on the App Store.
So far, I can't find the reason why this doesn't happen on testflight and only happens when I send it to review. I opened a ticket to Apple Developer Support and haven't recieved a response. I asked app review about it and they replied
"Hello,
Thank you for your response. Since all apps must pass App Review before they can be approved, it should not be necessary to have a "store page".
We look forward to reviewing your app once all issues have been addressed and the new build has been received and queued for review.
Best regards,
App Review"
Which doesn't really help me. I am quite pressed for time and I really need assistance in resolving this issue which I cannot replicate. Has anyone encountered this issue or know how to solve it?
Finally, I was able to upload a release candidate (version 1.0.0) Friday night. Fingers crossed, they've again rejected my app, but this time it was due to another error unrelated to the GameCenter login.
After checking the PlayFab instance, I also saw that there was a NEW account created. 📣📣📣📣
Eventually, I found out that PlayFab has a hard limit when it comes to the player's display name which is 25 characters in length. This was also the reason why it crashed this time.
My logs showed that the player name was "Frank Lion of Hairy Outpost".
I assume that's some kind of "default" name suggestion whenever you have no GameCenter account yet.
Nevertheless, all I can tell is that it finally works and Apple did neither admit that they have had an issue nor that it was my fault. "It just works" is what I've read across so many forum posts here and there.
I assume, that someone from Apple has all the knowledge and just fixed it silently.
I hope, that your issue is fixed as well.
Wish you all the best!