MPI Error: "Invalid count" during 3D Basilisk simulation

[Nivesh Mishra]

Hello Basilisk users,

I am encountering the following MPI error while running a 3D Basilisk simulation on my cluster:

Abort(201996034) on node 59 (rank 59 in comm 0): Fatal error in internal_Recv: Invalid count, error stack:
internal_Recv(50372): MPI_Recv(buf=0x149e273b5010, count=-2033828408, MPI_BYTE, 60, 256, MPI_COMM_WORLD, status=0x1) failed
internal_Recv(50302): Negative count, value is -2033828408
Abort(470416642) on node 60 (rank 60 in comm 0): Fatal error in internal_Isend: Invalid count, error stack:
internal_Isend(48736): MPI_Isend(buf=0x14884b8e7010, count=-2033828408, MPI_BYTE, 59, 256, MPI_COMM_WORLD, request=0x7ffcffdfeddc) failed
internal_Isend(48680): Negative count, value is -2033828408

This happens during the early stages of the run, after grid adaptation and data exchange between MPI ranks.

Could you please help me understand the possible root causes of this “Invalid count” error?

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