Ciao Marco, now it works and everything seems to be fine. I don’t know hap it is possible because I didn’t change anything… So weird! Anyway… Thanks for having helped me! I’ll try to generate other processes (e.g. p p > t t~ with 2 extra jets)… I’ll let you know if I find other issues. Cheers, Francesco On 27 Jan 2015, at 08:32, marco zaro <