Hello Yann,
As told in other topics, if you look at the PE*LOG files, the subdomain which may be suspicious and where the error may occur with extra error message is the one (or the ones) which has/have a different size.
Moreover, with my OS, I have an error message for the master proc, like:
application called MPI_Abort(MPI_COMM_WORLD, 2) - process 32
Traceback (most recent call last):
and it gives me the number of the subdomain where an error may occur: 32 in that case.
Hope this helps,
Chi-Tuan