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) April 19, 2022 at 10:23 am #6476 AdrianKeymaster As per the referenced issue: If you only care about suppressing the error, setting OMPI_MCA_btl_vader_single_copy_mechanism=none seems to work.