nobody can debug such a "monster" (in size of script lines and in size of
the system), and most definitely nobody on this mailing list will do this.
i also see things and features that could be disabled (e.g. tiled
communication, load balancing), since they are optional.
you are just asking for trouble.
have you tested whether your approach will work with a much(!) smaller test
system before embarking on this massive simulation?
what exactly is the reason why you define so many regions and fixes?
couldn't you just use fix efield with atom style variables?
please note, that LAMMPS has no limit as to the number of lines (or the
length of a line).
you may be hitting a limit of the MPI library. are you using the -in flag
or I/O redirection?