PYTHIA8=parton_shower
change this in the run_card and see if that works. maybe MC@NLO for herwig6/pp is not supported anymore because it's too old.
then what you have to assure yourself is that you want to shower LHE file with pythia8, not herwig
PYTHIA8= parton_ shower
change this in the run_card and see if that works.
maybe MC@NLO for herwig6/pp is not supported anymore because it's too old.
then what you have to assure yourself is that you want to shower LHE file with pythia8, not herwig