How can I login to google-plus using google-plus-i

I am developing an iPhone application using Google Plus.

When I try to login, I get a 401 error.

I used google-plus-ios-sdk-1.7.1 sdk.

-(BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{

// Override point for customization after application launch.

    [GPPSignIn sharedInstance].clientID = kClientID;
    // Read Google+ deep-link data.
    [GPPDeepLink setDelegate:self];
    [GPPDeepLink readDeepLinkAfterInstall];    

    return YES;
}

In the shareviewcontroller:

-(void)viewDidLoad
{
    [super viewDidLoad];


    GPPSignIn *signIn                   = [GPPSignIn sharedInstance];
    signIn.shouldFetchGooglePlusUser    = YES;
    signIn.scopes                       = @[ kGTLAuthScopePlusLogin ]; 
    signIn.delegate                     = self;    

    [[GPPSignIn sharedInstance] trySilentAuthentication];

    _shareConfiguration                 = [ShareConfiguration sharedInstance];
    _shareConfiguration.useNativeSharebox = YES;
    //_shareConfiguration.deepLinkEnabled = YES;
    _shareConfiguration.mediaAttachmentEnabled = YES;
}

-(void)btnGoogleShare_Action
{

    if ([GPPSignIn sharedInstance].authentication) {
        id<GPPShareBuilder> shareBuilder = [[GPPShare sharedInstance] nativeShareDialog];
        [(id<GPPNativeShareBuilder>)shareBuilder attachImage:self.imgView.image];
        [(id<GPPNativeShareBuilder>)shareBuilder setTitle:self.dict[@"title"] description:self.dict[@"comment"] thumbnailURL:nil];
        [shareBuilder open];
    }
    else
    {
        AppDelegate *appDelegate = (AppDelegate*)[UIApplication sharedApplication].delegate;

        GPPSignInButton *sign = [[GPPSignInButton alloc] init];

        if (floor(NSFoundationVersionNumber) > NSFoundationVersionNumber_iOS_6_1) {

            appDelegate.alert = [[UIAlertView alloc] initWithTitle:@"Sign to Google +" message:@"After login to Google+, Please retry again." delegate:nil cancelButtonTitle:nil otherButtonTitles:@"Cancel", nil];

            [appDelegate.alert setValue:sign forKey:@"accessoryView"]; //works only in iOS7
        } else {

            appDelegate.alert = [[UIAlertView alloc] initWithTitle:@"Sign to Google +" message:@"After login to Google+, Please retry again.\n\n\n" delegate:nil cancelButtonTitle:nil otherButtonTitles:@"Cancel", nil];

            sign.frame = CGRectMake(70, 85, 100, 40);
            [appDelegate.alert addSubview:sign];
        }


        [GPPSignInButton class];
        [appDelegate.alert show];
    }
}

Below is a screenshot, can anyone help me?

As it mentioned in the comments, first problem is already discussed here.

Second problem about text and media simultaneously post is mentioned in API documentation for GPPNativeShareBuilder Protocol Reference. According to this documentation you can't use attachImage with setTitle function. Function setPrefillText could resolve your issue.