UPDATED to add Windows-based servers as another class of device that might have connection trouble next week.
Old Macs, iPhones, PlayStation 3 and Nintendo 3DS gaming consoles, an unknown number of smart TVs, set-top boxes and other “smart” devices, and even some PlayStation 4s may lose some internet connectivity next week.
That’s because a widely used digital certificate used to verify secure internet connections expires on Sept. 30, and millions of older devices won’t be able to update to install newer certificates.