I recently sideloaded the Nougat preview for the Mi Box.

However, after installing the beta, the Mi Box thinks that an older security update is available for the device (Patch Date July 2017).

And when it installs, I get an error.

Is there any way for me to roll back to 6.0, or the original firmware?

(A factory reset won’t help, because it keeps Nougat. And I can’t use recovery mode, because the remote won’t function when in that state.