I am using MPICH 3.3.2 on Centos 3.10, Torque 5.1.1. I have never seen this error when running my MPI jobs as myself, but when other users run the same code, this error may or may not occur. It seems to happen when the job is shutting down. [[email protected]] HYDU_sock_write (utils/sock/sock.c:256): write error (Bad file descriptor) [[email protected]] HYD_pmcd_pmiserv_send_signal (pm/pmiserv/pmiserv_cb.c:178): unable to write data to proxy [[email protected]] ui_cmd_cb (pm/pmiserv/pmiserv_pmci.c:77): unable to send signal downstream [[email protected]] HYDT_dmxu_poll_wait_for_event (tools/demux/demux_poll.c:77): callback returned error status [[email protected]] HYD_pmci_wait_for_completion (pm/pmiserv/pmiserv_pmci.c:196): error waiting for event [[email protected]] main (ui/mpich/mpiexec.c:336): process manager error waiting for completion Does anyone have a clue what these errors mean? I hope this is enough info to go on. If not, please let me know what else I should provide. Thanks, Kurt