Its pretty obvious.. Null pointer exception means you're trying to access object that is set to null.  Line number at which it is thrown would be nice.

Also, unless you're planning on making the game for more than desktop, I would suggest to use only LWJGL. From my experience at least, Libgdx is a mess to work with..

Why do you think it's a mess to work with?

I just want to know why think that it's a mess 

I can make a little list of stuff that I really hated..
* Multiple projects. Always have to wait 5 seconds after editing image or press refresh on android project.
* Cannot access original LWJGL GL classes. They put stuff into glcommon, gl11, gl20. They didn't put everything.
* Cannot use GL11 and GL20 at the same time.
* You only get 1 method for updating your game: only render, no tick/update method. Cannot render at maximum speed. Always capped at 60 fps.
* I couldn't find a way to measure performance.
* Shaders are stupid or what? Gives errors when LWJGL doesn't. I mean, when I load shader into Libgdx, it "works" differently than in LWJGL. Variables that do not affect the output of the shader are not compiled to the shader. This is probably to boost performance, but is really annoying. Could have just given warnings telling that some uniforms are not used.
* Sprite class doesn't have anti bleeding built in.

These are the most annoying things that are just keeping me from using Libgdx..
I'm not saying Libgdx is shit.. I just don't like it.. It makes developing more like a drill to me. There is always that stupid something that doesn't need to be there..
Of course, Libgdx has much more upsides than it has down ones.. I just happen not to like it. Its like choosing operating system.. You don't choose it, because its better. You choose it, because you like it more.

You choose a tool based on what it provides for you, i.e, based on your needs. Learning the peculiarities of a library/tool that provides the things you need is what most of programming is about - especially game development.

If you don't like it - do it yourself. Perhaps in 10 years you will be able to reinvent the bicycle.




Additionally, comparing libGDX to LWJGL is like:

I might be in the wrong, but are you suggesting me to do multi threaded game, because Libgdx couldn't make 2 separate methods?
Did you try counting fps? You will never count higher than 60.
Well which texture filters am I supposed to use to get rid of bleeding? Would be really willing to learn those..

Instant 1600 FPS, not that you need any more than the default 60, and excessive frame rate only burns up your graphics card.

Google libgdx vsync, and read the docs before making assumptions.

Why "multi threaded game", I think GL20 and GL11 are seperate because of cross-plattform performance.
If you really want to, you can add lwjgl jars and access interfaces directly.
As you can have your own render-game-whatever loop you can get as much fps as you want.
Vsync is enabled by default because it needs a lot of energie and mobile-bateries won't do it long.
If you have texture-bleeding you can reduce it by using texturefilter-nearest instead of linear (if you texture isn't resized to strong).
Of course it doesn't solve the problem completely, but in most of my cases it helped and if you add padding to your textures it works fine. In addition Sprite.class is just made for drawing a textureregion you have to care about the accuracy yourself.

Its not fair to compare LWJGL to LibGDX, but its also not fair to bash LWJGL. Of course its difficult to use, get over it or don't use it. I'm quite sick of people bashing libraries and saying this one sucks etc... Use what you want and get over it. Thank you.

As mentioned in the other thread, this is done by the shader compiler, which is part of the graphics driver not of the library that you are using (http://ogltotd.blogspot.de/2007/12/active-shader-uniforms-and-vertex.html). The fact that this might work under LWJGL is because you don't check for your assigment going wrong, which lidGDX seems to do for you. You can ignore this as long as you like, but why don't you simply fix your stuff by not assigning values to uniforms that you don't use instead of blaming the library?

Graphics card can force it as well, check your settings, either that or your hardware is dated, sound like it because when I refresh or clean all my projects (which I have about 20) it's pretty much instantaneous.

Everybody should be allowed to express their opinion and criticize even libgdx without people jumping down your throat.
however disappointingly your complains weren't professional and all seemed to stem from ignorance rather than actual technical suggestions.

You never want to draw faster than your monitors refresh rate... right ? that would be stupid. so what the deal ?
Even if you have 120hz monitor im sure you can sync to 120 via vsync if thats at all desirable.

Wow hm. I guess you dont really understand how bleeding happens - which is ok its not immediately obvious since its low level; Point is: its not the sprite classes fault.