Error while implementing ISR effect in e-e+ -> mu- mu+

Hi Experts,
I am trying to simulate e-e+ > mu-mu+ using MadGraph5. The version I am using is 3.5.1. The syntax used to generate the events are as follows,
generate e- e+ > mu- mu+
output eemumu_isr
launch eemumu_isr
set lpp1 -3
set lpp2 +3
pdflabel = isronlyll

I paste the error output below.
```
INFO: Remember that Parton-Shower are not yet ready for such proton component definition (HW implementation in progress).
INFO: Update the dependent parameter of the param_card.dat
Generating 10000 events with run name run_01
survey run_01
INFO: compile directory
compile Source Directory
Using random number seed offset = 21
INFO: Running Survey
Creating Jobs
Working on SubProcesses
INFO: Compiling for process 1/1.
INFO: P1_ll_ll
INFO: P1_ll_ll
INFO: Idle: 1, Running: 0, Completed: 0 [ current time: 04h16 ]
INFO: Idle: 0, Running: 0, Completed: 1 [ 21.5s ]
INFO: Idle: 0, Running: 0, Completed: 1 [ 21.5s ]
INFO: End survey
refine 10000
Creating Jobs
INFO: Refine results to 10000
INFO: Generating 10000.0 unweighted events.
sum of cpu time of last step: 22 seconds
INFO: Effective Luminosity 1.2e+103 pb^-1
INFO: need to improve 0 channels
Survey return zero cross section.
   Typical reasons are the following:
   1) A massive s-channel particle has a width set to zero.
   2) The pdf are zero for at least one of the initial state particles
      or you are using maxjetflavor=4 for initial state b:s.
   3) The cuts are too strong.
   Please check/correct your param_card and/or your run_card.
Zero result detected: See https://cp3.irmp.ucl.ac.be/projects/madgraph/wiki/FAQ-General-14
```
Any comments or suggestions are highly appreciated.

Thanks and Regards!!!