问cloudbase开发flutter应用，无法获取登陆状态，怎么解决？

//导入这两个与cloudbase相关的包
import 'package:cloudbase_core/cloudbase_core.dart';
import 'package:cloudbase_auth/cloudbase_auth.dart';

然后连接cloudbase的代码参考文档的。

CloudBaseCore core = CloudBaseCore.init({...});//确保没有问题
CloudBaseAuth auth = CloudBaseAuth(core);

想使用auth.getAuthState();方法时，出现报错

E/flutter ( 5091): [ERROR:flutter/lib/ui/ui_dart_state.cc(199)] Unhandled Exception: Null check operator used on a null value

E/flutter ( 5091): #0 MethodChannel.binaryMessenger (package:flutter/src/services/platform_channel.dart:142:86)

E/flutter ( 5091): #1 MethodChannel._invokeMethod (package:flutter/src/services/platform_channel.dart:148:36)

E/flutter ( 5091): #2 MethodChannel.invokeMethod (package:flutter/src/services/platform_channel.dart:331:12)

E/flutter ( 5091): #3 MethodChannel.invokeMapMethod (package:flutter/src/services/platform_channel.dart:358:49)

E/flutter ( 5091): #4 MethodChannelSharedPreferencesStore.getAll (package:shared_preferences_platform_interface/method_channel_shared_preferences.dart:54:22)

E/flutter ( 5091): #5 SharedPreferences._getSharedPreferencesMap (package:shared_preferences/shared_preferences.dart:191:57)

E/flutter ( 5091): #6 SharedPreferences.getInstance (package:shared_preferences/shared_preferences.dart:58:19)

E/flutter ( 5091): #7 CloudBaseStore.init (package:cloudbase_core/src/store.dart:12:38)

E/flutter ( 5091): #8 AuthCache.getStore (package:cloudbase_auth/src/cache.dart:48:39)

E/flutter ( 5091): #9 CloudBaseAuth.getAuthState (package:cloudbase_auth/src/index.dart:99:39)

E/flutter ( 5091): #10 main (package:blossom_audio/main.dart:26:14)

E/flutter ( 5091): #11 _runMainZoned.<anonymous closure>.<anonymous closure> (dart:ui/hooks.dart:142:25)

E/flutter ( 5091): #12 _rootRun (dart:async/zone.dart:1354:13)

E/flutter ( 5091): #13 _CustomZone.run (dart:async/zone.dart:1258:19)

E/flutter ( 5091): #14 _runZoned (dart:async/zone.dart:1789:10)

E/flutter ( 5091): #15 runZonedGuarded (dart:async/zone.dart:1777:12)

E/flutter ( 5091): #16 _runMainZoned.<anonymous closure> (dart:ui/hooks.dart:138:5)

E/flutter ( 5091): #17 _delayEntrypointInvocation.<anonymous closure> (dart:isolate-patch/isolate_patch.dart:283:19)

E/flutter ( 5091): #18 _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:184:12)

E/flutter ( 5091):

谢谢！