Hello,
I've installed Pythia8 from within Madgraph, and Delphes separately, then moved my Delphes directory into the main Madgraph directory. When I generate events through the CLI by running ~/MG5_aMC_v_6_5/bin/mg5_aMC , I can turn on showering and detector simulation, and everything runs as expected. However, when I then try to generate additional runs from the output directory of the simulation, using <output>/bin/generate_events, the CLI comes up, but claims 'Delphes program installed but no parton shower module detected. Please install pythia8' , and showering and detector simulation are not available to select. I've checked in the <output>/Cards/me5_configuration.txt , and the pythia8_path and mg5_pythia8_interface paths are ./HEPTools/pythia8 and ./HEPTools/MG5aMC_PY8_interface, which I believe are correct. Both of those directories exist in the main Madgraph directory, so I'm not sure why Pythia can't be found. I've used /generate_events before on a different machine, without issues.