I’ve resolved mine.
Running the last command manually it showed the error bellow:
Apple-TV:~ root# apt-get -y install com.firecore.maintenance
Reading package lists… Done
Building dependency tree
Reading state information… Done
E: The package org.xbmc.xbmc-ios needs to be reinstalled, but I can’t find an archive for it.
So I removed this with:
dpkg --remove --force-remove-reinstreq org.xbmc.xbmc-ios
and then the atv flash black installer worked.
It might be because I moved over from the org.xbmc.xbmc-ios to org.xbmc.xbmc-atv2 and there was something left behind?