Background on app does not load

I am making an app, my first app, but I have run into a problem I don't know how to fix. Whenever I test my app on the simulator, it works fine, but when I test it on my iPod touch 4th gen, it gives me errors. It still compiles and run, but ends up having a black background instead of the background I tried to put in. Also, the loading screen uses the same images, and works fine. I am running the newest version of xcode.

Here is the error:

This is the code I used to put the background in:

All the images are there:

Here are the settings that I use on my views in the storyboard:

Those settings were default.

Does anyone know why this would be happening? If so, how would I fix it? Like I said, this is my first app, and I am very new to xcode and ob-c, so I might just be making an obvious mistake. Thanks!