Trouble-shooting
If you are having issues with MadMiner, please go through the following check list:
Event generation crashing
Is MadGraph correctly installed? Can you generate events with MadGraph on its own, including the reweighing option?
If you are using Pythia and Delphes: Are their installations working? Can you run MadGraph with Pythia, and can you run Delphes on the resulting HepMC sample?
If you are using PDF or scale uncertainties: Is LHAPDF installed with Python support?
Key errors when reading LHE files
Do LHE files contain multiple weights, one for each benchmark, for each event?
Zero events after reading LHE or Delphes file
Are there typos in the definitions of required observables, cuts, or efficiencies? If an observable, cut, or efficiency causes all events to be discarded, DEBUG-level logging output should help you narrow down the source.
Neural network output does not make sense
Start simple: one or two hidden layers are often enough for a start.
Does the loss go down during training? If not, try changing the learning rate.
Are the loss on the training and validation sample very different? This is the trademark sign of over-training. Try a simpler network architecture, more data, or early stopping.