Error in simulation-1st time

[18nanma]

========================== F E P X ==========================
Info : A finite element software package for polycrystal plasticity.
Info : Version 2.0.1-1
Info : Running on 1 cores.
Info : https://fepx.info/
Info : Copyright (C) 1996-2023, DPLab, ACME Lab, CNRS.
Info : ---------------------------------------------------------------
Info : Start time: 2024-8-28 at 22:22
Info : Loading simulation...
Info : [i] Parsing file simulation.cfg'... Info : - Material parameters: Info : > Number of phases: 1 Info : > phase 1 - crystal type: fcc Info : > m: 0.500000E-01 Info : > gammadot_0: 0.100000E+01 Info : > h_0: 0.200000E+03 Info : > g_0: 0.210000E+03 Info : > g_s0: 0.330000E+03 Info : > n: -0.100000E+01 Info : > c11: 0.245000E+06 Info : > c12: 0.155000E+06 Info : > c44: 0.625000E+05 Info : [i] Parsed file simulation.cfg'.
Info : [i] Parsing file simulation.msh'... Info : - Mesh parameters: Info : > Node number: 4008 Info : > Elt number: 2453 Info : [i] Parsed file simulation.msh'.
Info : Initializing simulation...
cp: -r not specified; omitting directory 'simulation.sim'
cp: cannot stat '*.sh': No such file or directory
Info : - Initializing fields from isotropic viscoplastic solution
Info : > solveit_vp: Iteration 1
Info : . Solving NL iteration... R = NaN (1 iters)
Error : Residual is NaN.

Program aborted. Backtrace:
#0 0x7d489d32b960 in ???
#1 0x7d489d32c41d in ???
#2 0x7d489d58f68c in ???
#3 0x5885ed860b11 in ???
#4 0x5885ed7c1401 in ???
#5 0x5885ed71b33f in ???
#6 0x5885ed71a5fe in ???
#7 0x7d489cf24d8f in ???
#8 0x7d489cf24e3f in ???
#9 0x5885ed71a634 in ???
#10 0xffffffffffffffff in ???