Hi Keith, liangshang Thanks I found a way to reproduce the problem. The problem occurs ONLY if the generation of the directory is done like MG4 (i.e. doing cp -r Template NAME) and not via the MG5 command line (i.e. ./bin/mg5 proc_card.dat or interactive interface) So this is a perfect time to pass to official MG5 methods and drops the MG4 retro-compatible method of generation. Cheers, Olivier Ok the problem occur only when generating processes in MG4 like way. On Sep 13, 2013, at 12:50 AM, Keith Pedersen