Crashing after change the viewController iOS4.3 - ios

Question

I wanted to know why I have this crash in my iOS app (deployment target iOS 4.3 - xcode 4).
I tested in iPad simulator 5.0 to 6.1 and worked 100% but in my iPad with iOS 4.3 (well, it's not mine so I can't update the iOS but it's good to practice with old iOS version) crash the app saying this:
2013-02-07 16:07:45.093 GeoRuta[169:707] -[mainViewController presentViewController:animated:completion:]: unrecognized selector sent to instance 0x331960
2013-02-07 16:07:45.113 GeoRuta[169:707] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[mainViewController presentViewController:animated:completion:]: unrecognized selector sent to instance 0x331960'
*** Call stack at first throw:
(
0 CoreFoundation 0x30f8064f __exceptionPreprocess + 114
1 libobjc.A.dylib 0x32828c5d objc_exception_throw + 24
2 CoreFoundation 0x30f841bf -[NSObject(NSObject) doesNotRecognizeSelector:] + 102
3 CoreFoundation 0x30f83649 ___forwarding___ + 508
4 CoreFoundation 0x30efa180 _CF_forwarding_prep_0 + 48
5 GeoRuta 0x00003781 -[mainViewController saltarConfiguracion:] + 184
6 CoreFoundation 0x30ef0571 -[NSObject(NSObject) performSelector:withObject:withObject:] + 24
7 UIKit 0x3575eec9 -[UIApplication sendAction:to:from:forEvent:] + 84
8 UIKit 0x3575ee69 -[UIApplication sendAction:toTarget:fromSender:forEvent:] + 32
9 UIKit 0x3575ee3b -[UIControl sendAction:to:forEvent:] + 38
10 UIKit 0x3575eb8d -[UIControl(Internal) _sendActionsForEvents:withEvent:] + 356
11 UIKit 0x3575f423 -[UIControl touchesEnded:withEvent:] + 342
12 UIKit 0x3575dbf5 -[UIWindow _sendTouchesForEvent:] + 368
13 UIKit 0x3575d56f -[UIWindow sendEvent:] + 262
14 UIKit 0x35746313 -[UIApplication sendEvent:] + 298
15 UIKit 0x35745c53 _UIApplicationHandleEvent + 5090
16 GraphicsServices 0x31a4de77 PurpleEventCallback + 666
17 CoreFoundation 0x30f57a97 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 26
18 CoreFoundation 0x30f5983f __CFRunLoopDoSource1 + 166
19 CoreFoundation 0x30f5a60d __CFRunLoopRun + 520
20 CoreFoundation 0x30eeaec3 CFRunLoopRunSpecific + 230
21 CoreFoundation 0x30eeadcb CFRunLoopRunInMode + 58
22 GraphicsServices 0x31a4d41f GSEventRunModal + 114
23 GraphicsServices 0x31a4d4cb GSEventRun + 62
24 UIKit 0x35770d69 -[UIApplication _run] + 404
25 UIKit 0x3576e807 UIApplicationMain + 670
26 GeoRuta 0x000030a9 main + 172
27 GeoRuta 0x00002ff8 start + 40
)
terminate called after throwing an instance of 'NSException'
The selector is:
- (IBAction) saltarConfiguracion: (id)sender
{
configuracionViewController *obj = [[configuracionViewController alloc]initWithNibName:#"configuracionViewController" bundle:nil];
[self presentViewController:obj animated:YES completion:nil];
}

Answer 1

Because [self presentViewController:obj animated:YES completion:nil] is a new iOS 5 methods. You can't use it on iOS 4. Instead, try calling [self presentModalViewController:obj animated:YES] (something like that)