Failed to read LHEF event information

Dear Basabendu,

first of all this is not an error but rather a warning.
Secondly, this warning is related to the fact that you have requested in Pythia to generate more events
than you have generated with the CalcHEP. If you will generate more events with the CalcHEP
than you will request at PYTHIA level, this warning should not appear.
Please let us know if this solves your problem. And, please, let me know if you have further questions.

Regards,
         Alexander

Dear Professor Belyaev,

                                               Thank you so much for the reply. I am generating 20,000 events with calcHEP and asking Pythis to generate same number of events. Should I use less number of events while working in Pythia?

Dear Basabendu,

I suggest you to generate slightly more than 20k events with CalcHEP, say 21k,
then ask PYTHIA to generate 20k events. In this case I do not expect you to have this warning.
The point is that few events in PYTHIA (~ 0.1% or so) could fail because of fragmentation or decay
failures, so you need slightly more events than 20k from the beginning to have 20k events after the PYTHIA

Regards,
     Alexander

Dear Professor Belyaev,

                                                Thank you so much. This solves my problem indeed. But I do have a question : Is there any upper limit of number of events generated by CalcHEP or Pythia?

Dear Basabendu,
There is no upper limit for events for CalcHEP or PYTHIA.
Le me know if you have any further questions.
If not, please indicate this in the status of this topic.
Regards,
 Alexander

The problem was solved