[Help] Using the Microsoft GameState Management Sample, I’m trying to create a menu with Textures instead of text.

Microsoft sample here.

I am a beginner. Basically I'm trying to have a menu with images of "Start" and "Exit", not text. I searched for two days where my mistake is and I can't find it. I rewrote the code countless times but I keep getting the same error.

My code raises an NullReferenceException, I think because my ContentManager is null.

I made a gist, but if that helps, you can download the full project here.

Thanks you guys for your attention.