Dear Xin, thank you very much for your efforts! Indeed, the test-bed code works out within your recent fix. However, my real application now is failing with the following error message: Assertion failed in file src/mpid/ch3/src/ch3u_handle_send_req.c at line 61: win_ptr->at_completion_counter >= 0 internal ABORT - process 10 Do you, by any chance, have any idea what might cause such error? Could you please advise me how to debug this problem? With best regards, Victor. _______________________________________________ discuss mailing list [email protected] To manage subscription options or unsubscribe: https://lists.mpich.org/mailman/listinfo/discuss