Thank you @mkelsey. In these days I installed Qt as you can red here https://geant4-forum.web.cern.ch/t/use-qt-with-geant-in-windows/ so I didn’t have Geant4. Moreover, now I’ve to do something more important (the flag is just a fuction that my supervisor wants, but it isnt’ important for the analysis, because I can just comment the lines for the moment).
I will try again the flag next days and I will update this topic