hi does any one know about this error : Fatal error in PMPI_Comm_rank: Invalid communicator, error stack: PMPI_Comm_rank(108): MPI_Comm_rank(comm=0x0, rank=0x7fff24a405bc) failed PMPI_Comm_rank(66).: Invalid communicator Fatal error in PMPI_Comm_rank: Invalid communicator, error stack: PMPI_Comm_rank(108): MPI_Comm_rank(comm=0x0, rank=0x7fff63e1598c) failed PMPI_Comm_rank(66).: Invalid communicator it is when i run mpich like : mpirun -np 2 ./coawstM swan_only.in i don't know if this is a problem in my executable file (coawstM) or this is from mpich or any other hardware issues or anything else thank you for your help nazi _______________________________________________ discuss mailing list [email protected] To manage subscription options or unsubscribe: https://lists.mpich.org/mailman/listinfo/discuss