[jlmcr87]

How can I downgrade form beta to stable?
Remote control is not working in recovery mode. I don´t know what to do. Thanks

I bet you have un-paired the remote mistakingly by pressing the Back Button and small middle "o" button.
Reboot the Mi Box completely and BT-pair it again. Remove the batteries if you have to.

OR

Attach a USB Keyboard.

OR Do some DIY and get down and dirty

Kodi cannot help you with Firmware DIY re-installs. You are now on your own.

With the xiaomi_update file it attempts to install the zip file, but gives an error in the middle of the process. Ok it doesn´t matter. I´m only worried about been able to install the final release of nougat via OTA or zip in the future.