glhelper | Helper & thin abstraction classes for OpenGL | Serialization library

So I'm currently trying to replace my old texture atlas stitcher with a 2D texture array to make life simpler with anisotropic filtering and greedy meshing later on.

I'm loading the png files with stb and I know that the buffers are filled properly because if I export every single layer of the soon to be atlas right before uploading it it's the correct png file.

My setup works like this:

I'm loading every single texture in my jar file with stb and create an object with it that stores the width, height, layer and pixelData in it.

When every texture is loaded i look for the biggest texture and scale every smaller texture to the same size as the biggest because i know that 2D texture arrays only work if every single one of the layers has the same size.

Then I initialize the 2d texture array like this:

glGetAttribLocation returns -1 on one of my 3 attributes (color). Checking for errors, state, etc and everything returns positive. Using OpenGL ES2 on Android 7. Just cannot find the cause and the way how color is set up is identical to texcoord for me.

Vertex Shader: