Failed to creat mesh file (.inp) in model -M

[Hugues-Zhang]

Here is my input code
##===========================================================================
neper -T -n from_morpho -id 20 -morpho "gg(0.01)" -dim 3 -domain "cube(0.05,0.05,0.05)" -reg 1 -o Zr_3d
neper -M Zr_3d.tess -elttype quad -cl 0.001 -format inp
##==========================================================================

and here is the reported information
##=====================================================================
Info : A software package for polycrystal generation and meshing.
Info : Version 3.5.2
Info : Built with: gsl|muparser|opengjk|openmp|nlopt
Info : Running on 1 threads.
Info : http://neper.info
Info : Copyright (C) 2003-2020, and GNU GPL'd, by Romain Quey.
Info : No initialization file found (/home/hugues/.neperrc'). Info : --------------------------------------------------------------- Info : MODULE -M loaded with arguments: Info : [ini file] (none) Info : [com line] Zr_3d.tess -elttype quad -cl 0.001 -format inp Info : --------------------------------------------------------------- Info : Reading input data... Info : - Reading arguments... Info : Loading input data... Info : - Loading tessellation... Info : [i] Parsing file Zr_3d.tess'...
Info : [i] Parsed file `Zr_3d.tess'.
Info : Meshing...
Info : - Preparing... (cl = 0.001) 100%

Info : - 3D meshing... 83%Killed
##=====================================================================

If I increse the element size like -cl 0.002, the program can carry out. BUT I want to created the mesh file with element size=0.001. how can I deal with this error? Waiting for your help! THANKS!

[Hugues-Zhang]

I have tried to change the number of threads by export OMP_NUM_THREADS =12, but notthing changed.