I have recently installed OpenMPI on my computer and when I try to run a simple Hello World program, it exits with the next error:

-------------------------------------------------------
Primary job  terminated normally, but 1 process returned
a non-zero exit code.. Per user-direction, the job has been aborted.
-------------------------------------------------------

This is the program's source code:

#include <mpi.h>
#include <stdio.h>

int main(int argc, char *argv[])
{
    int size, rank;

    MPI_Init(&argc, &argv);
    MPI_Comm_size(MPI_COMM_WORLD, &size);
    MPI_Comm_rank(MPI_COMM_WORLD, &rank);

    printf("Hello\n");

    MPI_Finalize();

    return 0;
}

This is how I compile the program:

mpicc -o hello hello.c

and I execute it with

mpirun -np 2 hello

It throws no errors on compilation, and if I run ./hello, it runs ok.

Excuse my english, any correction will be welcome.