Why does my foundation look so cakey and patchy?

Why does my foundation look so cakey and patchy? ( HowToBeHot / voltairee_ ) Whenever I put face makeup on it looks like this on my skin. Besides the pimples not being covered, why does it look so damn cakey? I used this same foundation / concealer 4 months ago when I was wearing makeup daily and it looked fine. Is foundation just old or something? Furthermore, any acne friendly makeups? why,does,foundation,look,cakey,and,patchy,why does foundation,look cakey and,patchy