SIGABRT thread error running simple ios app - ios

Question

Ok so there have been a lot of answers to questions like this but none of them have worked for me. Basically i have written a very simple iOS app that has a label and a button. click the button and the label changes. Here is the code
//ViewController.h
#import <UIKit/UIKit.h>
#interface ViewController : UIViewController
- (IBAction)buttonPressed:(id)sender;
#property (strong, nonatomic) IBOutlet UILabel *predictionLabel;
#end
//
// ViewController.m
// CrystalBall
//
//
//
#import "ViewController.h"
#implementation ViewController
#synthesize predictionLabel;
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Release any cached data, images, etc that aren't in use.
}
#pragma mark - View lifecycle
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
}
- (void)viewDidUnload
{
[self setPredictionLabel:nil];
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
}
- (void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
}
- (void)viewWillDisappear:(BOOL)animated
{
[super viewWillDisappear:animated];
}
- (void)viewDidDisappear:(BOOL)animated
{
[super viewDidDisappear:animated];
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
// Return YES for supported orientations
return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
}
- (IBAction)buttonPressed:(id)sender {
self.predictionLabel.text = #"Definitley Yes!";
}
#end
And when i run it in the simulator the app opens fine and then i click the "Predict" button and then it freezes and this is the error that shows up in green
Thread 1: Program recieved signal: "SIGABRT".
that is along a line that reads
return UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class]));
The debugger says:
2013-01-19 22:53:30.511 CrystalBall[441:f803] * Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[UIView setText:]: unrecognized selector sent to instance 0x6a19c70'
* First throw call stack:
2013-01-19 22:53:30.511 CrystalBall[441:f803] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[UIView setText:]: unrecognized selector sent to instance 0x6a19c70'
*** First throw call stack:
(0x13b9052 0x154ad0a 0x13baced 0x131ff00 0x131fce2 0x2385 0x13baec9 0x135c2 0x1355a 0xb8b76 0xb903f 0xb82fe 0x38a30 0x38c56 0x1f384 0x12aa9 0x12a3fa9 0x138d1c5 0x12f2022 0x12f090a 0x12efdb4 0x12efccb 0x12a2879 0x12a293e 0x10a9b 0x1da8 0x1d05)
terminate called throwing an exception(gdb)
Hopefully that is enough information. Thank you!

Answer 1

'-[UIView setText:]: unrecognized selector sent to instance 0x6a19c70'
means that you are trying to send the setText message to a UIView instance, which does not have any such method.
This possibly comes from the statement:
self.predictionLabel.text = #"Definitley Yes!";
so you should review how you defined predictionLabel and make sure that it is of the correct type.
About the fact that you the debugger is showing you the line:
return UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class]));
you should define an exception breakpoint in Xcode to catch all exceptions:
go to the breakpoints tab in the left-hand pane;
at the bottom of the pane, you will find a + icon;
click it and the select Add exception breakpoint;
confirm and it's done.
Now, the debugger shall stop on the actual line causing sigabrt so you can inspect your objects' state.