Can't enable the development installer!

I pressed the sequence on remote controller, and reached the page for "enable installer and restart". However, when I tried to enable it, it gives me error saying the device is not linked.

The weird part is that the device is actually linked! I linked it to my account, and I can see the device from my linked devices. From the device, I can browse channels without problems. It just gives error when I tried to enable the development installer.