Flutter Firebase working on simulator but apple review: an unknown error occurred please check the server response

Question

I am losing my mind here... I tested my Flutter app that uses Firebase and everything is working perfectly fine. On every simulator, on a real device, in TestFlight. Everything is working.

BUT the apple reviewer keeps getting an error when trying to upload something to Firebase but the error only says:

an unknown error occurred please check the server response

This is where the error occurs:

 Future<Memory?> addMemory({
    required BuildContext context,
    required String title,
    required List<String> imageFilePaths,
    required DateTime dateTime,
    required String? story,
    int? sortIndexIfEditing,
  }) async {
    try {
      Year currentYear =
          Provider.of<DataProvider>(context, listen: false).getCurrentYear();

      Month currentMonth =
          Provider.of<DataProvider>(context, listen: false).getCurrentMonth();

      int currentMonthIndex = currentMonth.month;

      String uid = AuthService.currentUser!.uid;

      List<String> imageLocations = [];

      for (String path in imageFilePaths) {
        String uidForLocation = Uuid().v1();

        String imageLocation =
            '$uid/${currentYear.id}/${currentMonth.id}/$uidForLocation';

        await FirebaseStorage.instance.ref(imageLocation).putFile(
              File(path),
            );
        imageLocations.add(imageLocation);
      }
      Memory? memoryToReturn = await _addMemoryToDatabse(
        context: context,
        imageLocations: imageLocations,
        currentYear: currentYear,
        currentMonthIndex: currentMonthIndex,
        title: title,
        dateTime: dateTime,
        story: story,
        sortIndexIfEditing: sortIndexIfEditing,
      );

      return memoryToReturn;
    } on FirebaseException catch (e) {
      print('addMemory failed: ' + e.message.toString());
      AlertService.showSnackBar(
        title: 'Ups, hier ist etwas schiefgelaufen...',
        description: e.message.toString(),
        isSuccess: false,
      );
      return null;
    }
  }

It is not about Security Rules, already checked that:

rules_version = '2'; 
service cloud.firestore { 
    match /databases/{database}/documents {
        match /{document=**} {
            allow read, write: if request.auth != null;
        }  
    } 
 }

What else can this error mean? I wish I could provide you with more information, but that's all I got.

Let me know your email if you want access to TestFlight, so you can test it yourself.

Answer 1

as Frank suggested, this is a known issue with Firebase Storage.

This is another SO-Question about the same case:

App Store review team reports 'Connection refused' error preventing image loading when using Firebase storage

Btw, my app just got accepted. I changed my Security Rules to allow read, write: if true which you SHOULD NOT do. After it got accepted I changed it back to a secure rule.

I don't know if there was an actual auth issue, because my Firebase-Log didn't show any rejections.