SKScene unarchiveFromFile Method crashing my app? - ios

Question

Okay so my app run perfectly fine in the simulator but when I plug in my device and try to run it on the real thing, I get this error:
Terminating app due to uncaught exception 'NSInvalidArgumentException',
reason: '*** -[_NSPlaceholderData
initWithContentsOfFile:options:error:]: nil file argument'
and its due to this method:
+ (instancetype)unarchiveFromFile:(NSString *)file {
/* Retrieve scene file path from the application bundle */
NSString *nodePath = [[NSBundle mainBundle] pathForResource:file ofType:#"sks"];
/* Unarchive the file to an SKScene object */
NSData *data = [NSData dataWithContentsOfFile:nodePath
options:NSDataReadingMappedIfSafe
error:nil];
NSKeyedUnarchiver *arch = [[NSKeyedUnarchiver alloc] initForReadingWithData:data];
[arch setClass:self forClassName:#"SKScene"];
SKScene *scene = [arch decodeObjectForKey:NSKeyedArchiveRootObjectKey];
[arch finishDecoding];
return scene; }
More specifically it is caused by the "pathForResource:file ofType:#"sks"
but I dont understand why this causes the error, or how else I am supposed to load my scene and use my app. If it helps, I am using GameScene.h to programatically make my scene, not the scene designer in xcode

Answer 1

It looks like that you want to access a file, which doesn't exists on the real device. Maybe you're accessing a file in a directory which the iOS-simulator can get(in Application Support-folder) but the real iOS device can't.
Check if there are any hard-coded paths in your code which could make this behaviour happen.

Answer 2

I was able to fix this by avoiding the use of the unarchiving method all together. Previously the scene was created with:
- (void)viewDidLoad
{
[super viewDidLoad];
// Configure the view.
SKView * skView = (SKView *)self.view;
skView.showsFPS = YES;
skView.showsNodeCount = YES;
/* Sprite Kit applies additional optimizations to improve rendering performance */
skView.ignoresSiblingOrder = YES;
// Create and configure the scene.
GameScene *scene = [GameScene unarchiveFromFile:#"GameScene"];
scene.scaleMode = SKSceneScaleModeResizeFill;
// Present the scene.
[skView presentScene:scene];
}
Now I changed that to this and it works fine on the real device:
- (void)viewDidLoad
{
[super viewDidLoad];
// Configure the view.
SKView * skView = (SKView *)self.view;
skView.showsFPS = YES;
skView.showsNodeCount = YES;
// Create and configure the scene.
SKScene * scene = [GameScene sceneWithSize:skView.bounds.size];
scene.scaleMode = SKSceneScaleModeResizeFill;
// Present the scene.
[skView presentScene:scene];
}