I can run 1.9.2 without an problems. As soon as I download 16w15b, I can no longer load worlds without crashing almost immediately, before any chunks are visible. This crash becomes systemic; even if I roll back to 1.9.2, it will still crash. I have to do a full uninstall and reinstall. As long as I stay on 1.9.2 I am fine. However, any world updated to 16w15b will cause the crash.

I've tried multiple Java versions without success.