About viscoelastic model

Dear Dr. Baagaard,

I hope this message finds you well. I am currently running the step06 example in the subduction directory. When using an elastic model, the calculations proceed without issues. However, when switching to a viscoelastic model—even the simplest uniform viscoelastic model—I encounter the following error:
[0]PETSC ERROR: --------------------- Error Message --------------------------------------------------------------
[0]PETSC ERROR:
[0]PETSC ERROR: KSPSolve has not converged due to NaN or Inf norm
[0]PETSC ERROR: See http://www.mcs.anl.gov/petsc/documentation/faq.html for trouble shooting.
[0]PETSC ERROR: Petsc Release Version 3.10.2, Jul, 01, 2019
[0]PETSC ERROR: /public1/home/t0s000462/xiaoy/Pylith/pylith-2.2.2-linux-x86_64/bin/mpinemesis on a named cb1101.para.bscc by t0s000462 Thu Nov 21 16:18:22 2024
[0]PETSC ERROR: Configure options --prefix=/home/brad/pylith-binary/dist --with-c2html=0 --with-x=0 --with-clanguage=C --with-mpicompilers=1 --with-shared-libraries=1 --with-64-bit-points=1 --with-large-file-io=1 --download-chaco=1 --download-ml=1 --download-f2cblaslapack=1 --with-hwloc=0 --with-ssl=0 --with-x=0 --with-c2html=0 --with-lgrind=0 --with-hdf5=1 --with-hdf5-dir=/home/brad/pylith-binary/dist --with-zlib=1 --LIBS=-lz --with-debugging=0 --with-fc=0 CPPFLAGS=“-I/home/brad/pylith-binary/dist/include -I/home/brad/pylith-binary/dist/include " LDFLAGS=”-L/home/brad/pylith-binary/dist/lib -L/home/brad/pylith-binary/dist/lib64 -L/home/brad/pylith-binary/dist/lib -L/home/brad/pylith-binary/dist/lib64 " CFLAGS=“-g -O2” CXXFLAGS=“-g -O2 -DMPICH_IGNORE_CXX_SEEK” FCFLAGS= PETSC_DIR=/home/brad/pylith-binary/build/petsc-pylith PETSC_ARCH=arch-pylith
[0]PETSC ERROR: #1 KSPGMRESCycle() line 125 in /home/brad/pylith-binary/build/petsc-pylith/src/ksp/ksp/impls/gmres/gmres.c
[0]PETSC ERROR: #2 KSPSolve_GMRES() line 234 in /home/brad/pylith-binary/build/petsc-pylith/src/ksp/ksp/impls/gmres/gmres.c
[0]PETSC ERROR: #3 KSPSolve() line 780 in /home/brad/pylith-binary/build/petsc-pylith/src/ksp/ksp/interface/itfunc.c
[0]PETSC ERROR: #4 void pylith::problems::SolverLinear::solve(pylith::topology::Field*, pylith::topology::Jacobian*, const pylith::topology::Field&)() line 132 in …/…/…/pylith-2.2.2/libsrc/pylith/problems/SolverLinear.cc
Fatal error. Calling MPI_Abort() to abort PyLith application.
Traceback (most recent call last):
File “/public1/home/t0s000462/xiaoy/Pylith/pylith-2.2.2-linux-x86_64/lib/python2.7/site-packages/pylith/apps/PetscApplication.py”, line 74, in onComputeNodes
self.main(*args, **kwds)
File “/public1/home/t0s000462/xiaoy/Pylith/pylith-2.2.2-linux-x86_64/lib/python2.7/site-packages/pylith/apps/PyLithApp.py”, line 138, in main
self.problem.run(self)
File “/public1/home/t0s000462/xiaoy/Pylith/pylith-2.2.2-linux-x86_64/lib/python2.7/site-packages/pylith/problems/TimeDependent.py”, line 155, in run
self.formulation.step(t, dt)
File “/public1/home/t0s000462/xiaoy/Pylith/pylith-2.2.2-linux-x86_64/lib/python2.7/site-packages/pylith/problems/Implicit.py”, line 212, in step
self.solver.solve(dispIncr, self.jacobian, residual)
File “/public1/home/t0s000462/xiaoy/Pylith/pylith-2.2.2-linux-x86_64/lib/python2.7/site-packages/pylith/problems/problems.py”, line 166, in solve
def solve(self, *args): return _problems.SolverLinear_solve(self, *args)
RuntimeError: Er/public1/home/t0s000462/xiaoy/Pylith/pylith-2.2.2-linux-x86_64/bin/nemesis: mpirun: exit 255
/public1/home/t0s000462/xiaoy/Pylith/pylith-2.2.2-linux-x86_64/bin/pylith: /public1/home/t0s000462/xiaoy/Pylith/pylith-2.2.2-linux-x86_64/bin/nemesis: exit 1
I suspect this issue may be related to the spatial database for the viscoelastic material model. I have attached my configuration and spatial database files for your reference. Could you kindly advise what might be causing this issue and how I might resolve it?

Thank you for your time and assistance!

Best regards,
file.zip (3.9 MB)