White screen after installing metabuttons

When I plug Metabuttons expander into the Meta Module (following the setup guide), MM won’t boot and I get just a white screen. I have the IO and WiFi expanders as well. Everything works until I plug in the buttons. I’ve triple checked the connections. Not sure what I should try next. Any help greatly appreciated.

Problem sovled I think! …unplugged and replugged and somehow it came to life.

Man, what a tangle this gets to be with all the expanders!