Hi Brent, Unfortunately, unless you can provide us with a reproducer, there is little we can do to find the issue. -- Hui Zhou From: Brent Morgan via devel <[email protected]> Date: Wednesday, January 13, 2021 at 3:20 AM To: [email protected] <[email protected]> Cc: Brent Morgan <[email protected]>, Robert Katona <[email protected]> Subject: [mpich-devel] mpich3 error Hello mpich dev support, I am receiving the following error in my MPI implementation, when I use 110+ threads. Assertion failed in file src/mpid/ch3/channels/nemesis/src/ch3_progress.c at line 567: !vc_ch->recv_active 0x7f7f870937 ??? ???:0 0x7f7f870957 ??? ???:0 0x7f7f8089cf ??? ???:0 0x7f7f854983 ??? ???:0 0x7f7f75a4f3 ??? ???:0 0x7f7f7cd8bf ??? ???:0 0x7f7f7cde0f ??? ???:0 0x7f7f78d577 ??? ???:0 0x7f7f6ea6cb ??? ???:0 0x7f7f6ea8f3 ??? ???:0 0x7f7f78c7ff ??? ???:0 0x7f7f6e9e6f ??? ???:0 0x7f7f6e9eb7 ??? ???:0 0x7f7f6ea033 ??? ???:0 0x55793fe47b ??? ???:0 0x55793f96b3 ??? ???:0 0x7f7f29908f ??? ???:0 0x55793f9a9b ??? ???:0 internal ABORT - process 171 Does this give a clue as to what I may be doing wrong? Thank you, Best, Brent