Loading a texture in android generates a NULL Pointer exception


I want to load an image in nifty GUI, the usual xml syntax is not working (which works fine on pc) probably because assets folder doesnt get copied in android.
[java] <image filename=“back.png” width=“100%” height=“100%”></image>

I tried loading the texture into the AssetManager by using, but again it generates a NULL pointer exception in android but works fine on pc. Please guide, my purpose is to load image in nifty on android…
Texture t = am.loadTexture(“back.png”);

log message

Please someone help. I’m still stuck with the same issue.
I may be loosing some basic. So kindly point some sources about how should I locate assets on android.
I have tried google but nothing worked for me so far…

For instance, this code runs perfect on pc but fails on android with the exception attached in image in the first post.

[java] Picture pic = new Picture(“HUD Picture”);
Texture t =assetManager.loadTexture(“Textures/images.jpg”);
Material mat = new Material(assetManager, “Common/MatDefs/Misc/Unshaded.j3md”);
mat.setTexture(“ColorMap”, assetManager.loadTexture(“Textures/back.png”));
// pic.setKey(t.getKey());
//pic.setImage(assetManager, “Textures/back.png”, true);
pic.setPosition(0, 0);

Texture should be a power of 2 (64,128,256,512 etc)