Kinda funny how this is true but there's a line of Mac OSes that can't connect to the App Store anymore so you can't upgrade the OS without manually downloading it off of an Apple help page.
It's not the end of the world, but I've had to help more than one person walk through this process cuz they're like "I can't update the OS????"
It's not the end of the world, but I've had to help more than one person walk through this process cuz they're like "I can't update the OS????"