xcode 7 json總是在目標中顯示錯誤C

我在Xcode 6.4上創建了一個項目。它工作正常。但是當我將Xcode升級到Xcode 7時，所有的JSON服務都無法正常工作，並且總是給我錯誤。這裏是我的代碼xcode 7 json總是在目標中顯示錯誤C

NSDictionary *get = @{@"name":name.text,@"username":username.text,@"mobile":phonenumber.text}; 
NSData* jsonData = [NSJSONSerialization dataWithJSONObject:get options:kNilOptions error:nil]; 
NSString *jsonInputString = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding]; 
NSString *post = [[NSString alloc]initWithFormat:@"r=%@",jsonInputString]; 

NSURL *url=[NSURL URLWithString:[NSString stringWithFormat:@"%@",registerUrl]]; 

NSData *postData = [post dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES]; 
NSString *postLength = [NSString stringWithFormat:@"%lu", (unsigned long)[postData length]]; 
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url cachePolicy:NSURLRequestReloadIgnoringCacheData timeoutInterval:120.0]; 
[request setURL:url]; 
[request setHTTPMethod:@"POST"]; 
[request setValue:postLength forHTTPHeaderField:@"Content-Length"]; 
[request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"]; 
[request setHTTPBody:postData]; 

NSError *error; 
NSURLResponse *response; 
NSData *responseData=[NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error]; 
if (responseData != nil) 
{ 

    NSMutableDictionary *jsonDict = (NSMutableDictionary *)[NSJSONSerialization JSONObjectWithData:responseData options:kNilOptions error:&error]; 
    NSLog(@"Json Dictionary =======%@",jsonDict); 
} 

if (error) 
{ 
    NSLog(@"error %@",error.description); 
}

它仍然是在Xcode的6

這裏做工精細的錯誤日誌