OpenLB – Open Source Lattice Boltzmann Code › Forums › on OpenLB › General Topics › Error Output When Running in Parallel (Mpirun) › Reply To: Error Output When Running in Parallel (Mpirun) January 24, 2022 at 2:18 pm #6268 AdrianKeymaster It is hard to tell you anything here without knowing how exactly you executed this and what exactly your program implements. Are you sure that you compiled in MPI mode using the correct compiler settings?