It looks like this is the reason: “All Mac Store Apps Stopped Working Due To Expired Security Certificate” http://techcrunch.com/2015/11/12/all-mac-store-apps-

It looks like this is the reason: “All Mac Store Apps Stopped Working Due To Expired Security Certificate” http://techcrunch.com/2015/11/12/all-mac-store-apps-stopped-working-due-to-expired-security-certificate/ http://techcrunch.com/2015/11/12/all-mac-store-apps-stopped-... https://news.ycombinator.com/item?id=10554700 https://news.ycombinator.com/item?id=10554700