It takes a lot of time to do simulate_mice.py if beam is started at the tracker0
I found that if one starts the simulation from the tracker0 area, use the geometry 70, and constant_solenoid mode, it takes several minutes to simulate one spill.
This was confirmed by Durga. (Sorry for selling him out)
I believe the error can be reproduced with the geometry file and configuration data cards I attached. Please remember to change the directory and file path before running.
P.S. If anybody gets blamed you may use this issue tracker as a coupon to asking for a beer from me.