First I got this problem:
LWJGLRenderer renderer = new LWJGLRenderer();
Caused by: java.lang.NullPointerException
at org.lwjgl.opengl.GL11.glGetInteger(GL11.java:1436)
at de.matthiasmann.twl.renderer.lwjgl.LWJGLRenderer.syncViewportSize(LWJGLRenderer.java:224)
at de.matthiasmann.twl.renderer.lwjgl.LWJGLRenderer.<init>(LWJGLRenderer.java:125)
I've read, that I should call Display.create() or Display.makeCurrent();
In both cases, I get an exception.