Hmm well there is something which I think might have changed.
This worked last week - and im using new nightly builds each day. Today this dosnt work :
Quad box1 = new Quad(30, 31);
Geometry blue = new Geometry("Box", box1);
Material mat1 = new Material(assetManager, "Common/MatDefs/Misc/SimpleTextured.j3md");
TextureKey key = new TextureKey("Interface/cursor.png", true);//Locator must be set to root directory
Texture texture = getAssetManager().loadTexture(key);
It throws : java.lang.IllegalArgumentException: Material parameter is not defined: texture
Yeah, everything is correct. The "texture" parameter is undefined inside the material. If you look inside SimpleTextured.j3md, you'll see that it has a m_ColorMap parameter that you should be using instead.