feature is not available for tet mesh regions

Hi guys, i have a problem with my simulation, I want to make a packing, the mesh has tets elements.
i don't know what is my problem

LIGGGHTS (Version LIGGGHTS-PUBLIC 3.0.7, compiled 2015-02-17-21:24:53 by lito based on LAMMPS 23 Nov 2013)
Created orthogonal box = (-2 -2 -2) to (2 2 2)
2 by 2 by 2 MPI processor grid
0 atoms in group nve_group
Fix particledistribution/discrete (id pdd1): distribution based on mass%:
pts1: d=2.000000e-01 (max. bounding sphere) mass%=30.000000%
pts2: d=6.000000e-01 (max. bounding sphere) mass%=70.000000%
Fix particledistribution/discrete (id pdd1): distribution based on number%:
pts1: d=2.000000e-01 (max. bounding sphere) number%=92.045455%
pts2: d=6.000000e-01 (max. bounding sphere) number%=7.954545%
Note: Skipping empty line in VTK mesh file
Note: Skipping empty line in VTK mesh file
Note: Skipping empty line in VTK mesh file
Note: Skipping empty line in VTK mesh file
0 atoms in group nve_group
Setting up run ...
INFO: Resetting random generator for region stone
ERROR on proc 7: This feature is not available for tet mesh regions (../region_mesh_tet.cpp:142)
--------------------------------------------------------------------------
MPI_ABORT was invoked on rank 7 in communicator MPI_COMM_WORLD
with errorcode 1.

NOTE: invoking MPI_ABORT causes Open MPI to kill all MPI processes.
You may or may not see output from other processes, depending on
exactly when Open MPI kills them.

Thanks for help,

williams