Before trying advanced methods, see if your manufacturer has an official update available for your specific model: Via Settings: Device Preferences System Update Check for update Manual Download:
However, the process of finding the correct "update android tv 4.4 4 to 5.0 download" can be confusing. Many manufacturers abandoned their older hardware. This guide will walk you through everything you need to know: whether your device can be updated, where to find the firmware, how to download it, and a step-by-step installation guide. update android tv 4.4 4 to 5.0 download
A: You’re trying to install an unofficial ROM on a locked bootloader. You need to unlock the bootloader or use a custom recovery. Before trying advanced methods, see if your manufacturer