Android Question Problem with libgdx

[stratus]

Because i decided to learn programming with libgdx, I write a very simple program.
The problem is the program works at the start ok,it loads the background image,but after few seconds i have nullpointer exception.
Any idea?

 

[Informatix]

When I run your app, I get this error:
com.badlogic.gdx.utils.GdxRuntimeException: Couldn't load file: back.png

 

[ilan]

in your example there is no File Folder. so no back.png image.
where do you store back.png?

 

[stratus]

I delete the back.png file by mistake before i upload the zip.Finally the problem with the nullpointer exception error solved by restarting the phone