Classic BlackBerry devices running on OS 7.1 or earlier will no longer be supported after Jan. 4, meaning the phones will effectively be rendered useless. The company reminded customers of the change in a notification on Dec. 22. “As a reminder, the legacy services for BlackBerry 7.1 OS and earlier, BlackBerry 10 software, BlackBerry PlayBook OS 2.1 and earlier versions, will no longer be available after January 4, 2022,” the company said. “As of this date, devices running these legacy services and software through either carrier or Wi-Fi connections will no longer reliably function, including for data, phone calls, SMS and 9-1-1 functionality.” The devices will no longer function because they lack the ability to receive over-the-air provisioning updates, Blackberry said. Applications including BlackBerry Link, BlackBerry Desktop Manager, and BlackBerry Blend will also have limited functionality. “We have chosen to extend our service until then [Jan. 4] as an expression of thanks to our …