I tried… it’s still the same. 
the change_box command changed very recently.
did you refer to the documentation that matches
your version of LAMMPS or the online documentation?
if i add your change_box command to an input
and run it with the current version of lammps it works.
please note that the online documentation always
refers to the latest version and check for warnings
about backward (in)compatibilities here:
http://lammps.sandia.gov/bug.html
cheers,
axel.