使用账号和密码注册时,报错101

报错信息Error code: 101, Error message: Class or object doesn't exists.
注册代码
try {
// create the user
LCUser user = LCUser();

       //设置用户名和密码
       user.username = usernameController.text;
       user.password = passwordController.text;

       // 设置邮箱和手机号,可选
       user.mobile = '+86${mobileController.text}';

       // 设置其他属性,同LCObject

       await user.signUp();

        // pop loading circle
        Navigator.pop(context);
      } catch (e) {
        // pop loading circle
        Navigator.pop(context);

        // display error message to user
        if (e is LCException) {
          print('Error code: ${e.code}, Error message: ${e.message}');
        } else {
          print('An error occurred: $e');
        }