Error MPI Abort on rank 0

Dear Sir,
I am working on SMD package of LAMMPS. My simulation box size is 1mmX1mm X0.5mm. I have about 75000 particles in total, with usage of 87 Mb per processor. I am using 4 processors in the MPI and it is running fine. But as I have been trying to reduce the cell size of the particles in the simulation box (from 20μm). However as I run the code it shows :

cutoff for pair smd/smd/tri_surface = 0.016283

Step Dt Time PotEng vz_ind fz_ind
0 1e-16 2e-16 0 0 0

"ERROR on proc 0: Substitution for illegal variable (…/input.cpp:529)

asking the same question over and over again isn't going to help, if
you don't pay attention to the answers you have been given.