Facebook Share Feed Dialog not longer visible it redirect again to My app from Facebook Native app

Question

Hi i Facing strange issue with Post image using Facebook feed share dialog. I am using this bellow code:-

-(IBAction)shaerFacebook
{

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *savedImagePath = [documentsDirectory stringByAppendingPathComponent:@"savedImage2.png"];

    NSURL *imageFileURL =[NSURL fileURLWithPath:savedImagePath];

    UIImage *imagetoshare=[UIImage imageWithData:[NSData dataWithContentsOfURL:imageFileURL]];

if ([FBDialogs canPresentShareDialogWithParams:params]) {

        // Present share dialog
        id<FBGraphObject> pictureObject =
        [FBGraphObject openGraphObjectForPostWithType:@"mypicture:picture"
                                                title:@"title"
                                                image:imagetoshare
                                                  url:imagetoshare
                                          description:@""];

        id<FBOpenGraphAction> action = (id<FBOpenGraphAction>)[FBGraphObject graphObject];
        [action setObject:pictureObject forKey:@"picture"];

        [FBDialogs presentShareDialogWithOpenGraphAction:action
                                              actionType:@"Photoshare:cook"
                                     previewPropertyName:@"picture"
                                                 handler:^(FBAppCall *call, NSDictionary *results, NSError *error) {
                                                     if(error) {
                                                         NSLog(@"Error: %@", error.description);
                                                     } else {
                                                         NSLog(@"Success");
                                                     }
                                                 }];



        // If the Facebook app is NOT installed and we can't present the share dialog
    }
}

it will navigate facebook native app show the dialog with image and withing one second it will redirect to my app i can not able to post. i do lots of Google but not getting solution. please help me out in this where did i mistake.

Is there any specific change in to facebook app.?