Fix Fatal iOS crash

I am AdHoc testing an iOS app on iPad mini and iPhone 4. The app worked fine 48 hours ago on both platforms but is now fatally crashing/freezing when I test on iPhone 4. The app lets you login to an apache server using php/json, take pics using the iOS camera, then upload the pics to a vertical UIScrollView where the pics are viewed as jpeg thumbs. From there you can tap a thumb and view it full screen.The app works perfectly on iPad but not on iPhone 4. The app crashes (either freezes or goes back to the home screen) when I tap a photo jpeg thumb in the UIScrollView to view it full screen. (this works fine on iPad testing).

All i want to do right now is view a photo fullscreen on iPhone 4 but the app keeps fatally freezing. The second I tap a photo on iPhone, the app freezes and the compiler highlights the following line of code in the application.

[api commandWithParams:[NSMutableDictionary dictionaryWithObjectsAndKeys:@"stream", @"command", IdPhoto,@"IdPhoto", nil] onCompletion:^(NSDictionary *json) { 

//after this line of code is a 
Thread 1. EXC_BAD_ACCESS(code=1,address=ox28)

This is also a line of code the compiler points to after the freeze/crash. (It high lights the above live half the time and this line other times with the same 'Thread 1' alert.

if([value isKindOfClass:[NSDictionary class]]) {