@mitu After trying all day and failing I will tell you what I did
I tried your solution and it didn't work
I started from 0 the two translation tutorials of the original post. In both I get this error at the end
/home/pi/EmulationStation/es-core/src/resources/font.cpp:17: font : :fontface : : fontface(resourcedata&&, int) : assertion `!err' failed
then try two possible solutions:
a) update retropie setup (dont work)
b) update emulationstation from source (work but back to english)
the only thing that works so that it is translated but the shutdown / restart menu does not work is to put in autostart.sh LANG=es_ES.UTF8 /home/pi/EmulationStation/emulationstation #auto
thank you for your patience