Frustrated, Alex searched forums. Some called it the "gatekeeper error." Here’s what he learned.

Alex had just bought a used Xiaomi phone. It was a great deal—perfect hardware, a vibrant screen, but it was tied to the previous owner’s MI account. To truly make it his own, Alex needed to unlock the bootloader, the first step to installing a custom ROM or simply freeing the device.

He opened Settings > Mi Account on the phone. The top showed an unfamiliar email—the previous owner’s. That confirmed it: the phone was still bound to someone else.