Error 1001: Unable to open input data file

The solver crashed when running the mfix standard example fluid_bed_tfm_3d.

I uploaded bug zip, I used DMP mode to solve, running on HPC under Linux environment, using INTEL XEON GOLD 6240. (54.5 KB)

In the stdout file:

 Error 1001: Unable to open input data file: fluid_bed_tfm_3d_1019.mfx^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@

Those NUL characters after the file name should not be appearing. I do not know exactly what caused this, but I suspect an incompatibility with either your Fortran compiler or OpenMPI. I see that you are using

gfortran:            GNU Fortran (GCC) 4.8.5 20150623 (Red Hat 4.8.5-36)
openmpi:             Intel(R) MPI Library for Linux* OS, Version 2018 Update 4 Build 20180823 (id: 18555)

while we test with

gfortran:            GNU Fortran (conda-forge gcc 13.2.0-2) 13.2.0
openmpi:             mpirun (Open MPI) 4.1.6

Can you try either:

  1. Upgrade to MFiX 23.3.1, which comes with GFortran and OpenMPI bundled? (You should upgrade anyhow, if possible)


  1. In the active MFiX environment, do
(mfix-23.2) conda install -c conda-forge gfortran openmpi

and rebuild the solver again?