MPI problem?

[Andreas Härtel]

Dear ESPResSo mailing list,

Maybe anyone has an idea to help us:
We are running ESPResSo on a cluster (BW cluster nemo).
Starting with November 29th, 2019 we have seen messages from the cluster 
management system saying: "Job does not exist on node". This does 
happend only for a few percent of the jobs!

Further, we see the message when starting ESPResSo:
--------------------------------------------------------------------------
An MPI process has executed an operation involving a call to the
"fork()" system call to create a child process.  Open MPI is currently
operating in a condition that could result in memory corruption or
other system errors; your MPI job may hang, crash, or produce silent
data corruption.  The use of fork() (or system() or other calls that
create child processes) is strongly discouraged.

The process that invoked fork was:

  Local host:          n3765 (PID 172209)
  MPI_COMM_WORLD rank: 0

If you are *absolutely sure* that your application will successfully
and correctly survive a call to fork(), you may disable this warning
by setting the mpi_warn_on_fork MCA parameter to 0.
--------------------------------------------------------------------------

We do not know about the existence of a connection between both.
Can anyone give us a hint?

Thank you and best regards,
Andreas