Getting (null) on the first element in JSON - ios

Question

I want to log the first element with his subject. If I call the method using [self doRequest] in viewDidload, it works perfectly.
But if I call the method in a if- statement, it returns (null).
Code:
//Do request method
NSString *host = #"api.blazor.nl";
if(![host hasPrefix:#"http://"] || ![host hasPrefix:#"https://"])
{
host = [#"http://" stringByAppendingString:host];
}
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:[NSString stringWithFormat:#"%#", host]] cachePolicy: NSURLRequestUseProtocolCachePolicy timeoutInterval:10.0f];
[request setHTTPMethod:#"GET"];
NSString *publickey = [[NSUserDefaults standardUserDefaults]
stringForKey:#"publicKey"];
NSString *privatekey = [[NSUserDefaults standardUserDefaults]
stringForKey:#"privateKey"];
NSLocale* currentLocale = [NSLocale currentLocale];
NSString* currentTime = [[NSDate date] descriptionWithLocale:currentLocale];
[request setValue:currentTime forHTTPHeaderField:#"x-api-time"];
[request setValue:publickey forHTTPHeaderField:#"x-api-public"];
[request setValue:privatekey forHTTPHeaderField:#"x-api-private"];
[request setValue:#"application/json" forHTTPHeaderField:#"Content-Type"];
NSURLSessionDataTask *urlSessionDataTask = [[NSURLSession sharedSession] dataTaskWithRequest:request completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
if(error)
{
NSLog(#"%#", error);
dispatch_async(dispatch_get_main_queue(), ^{
[self.activityIndicator stopAnimating];
UIAlertController *alertViewController= [UIAlertController alertControllerWithTitle:#"An error happened" message:nil preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction* closeAction = [UIAlertAction actionWithTitle:#"Close" style:UIAlertActionStyleDefault handler:^(UIAlertAction * action) {}];
[alertViewController addAction:closeAction];
[self presentViewController:alertViewController animated:YES completion:nil];
});
return;
}
NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse *) response;
NSInteger success = 1;
NSError *serializeError = nil;
NSDictionary *jsonData2 = [NSJSONSerialization
JSONObjectWithData:data
options:NSJSONReadingMutableContainers
error:&serializeError];
success = [jsonData2[#"ERROR"] integerValue];
if((long)[httpResponse statusCode] == 200){
[[NSUserDefaults standardUserDefaults] setBool:YES forKey:#"logged_in"];
}
if (success == 0) {
NSLog(#"%#", jsonData2[#"notifications"][0][#"thread"][#"subject"]);
NSLog(#"%#", jsonData2);
NSLog(#"%ld", (long)[httpResponse statusCode]);
}else{
}
}];
[urlSessionDataTask resume];
//if statement
if(count < someNumber) {
[self doRequest];
[[NSUserDefaults standardUserDefaults] setObject:someNumber forKey:#"count"];
} else {
NSLog(#"Number not samller then someNumber");
}
}
//Json:
notifications = (
{
content = "has quoted you in";
created = "2017-06-22T12:12:04+00:00";
id = "68b87954-77ae-4202-bb2f-2417a974fa57";
"reply_id" = 79811;
thread = {
id = 3294;
subject = "Ik erger me aan..... deel 2";
};
"thread_id" = 3294;
"users_from" = {
username = Moe;
};
}
);
}
What's wrong with the code?
Thanks.