MG5 v 2.5.5: Pythia8 stalls during shower job

Hi,
I am very new to MadGraph and have encountered a problem not allowing me to process the hadronisation and showering from partons using pythia8.

My pythia8 shower stalled at...

          Submitting Pythia8 jobs...
          Pythia8 shower jobs: 1 Idle, 0 Running, 0 Done [1 seconds]
          Pythia8 shower jobs: 0 Idle, 1 Running, 0 Done [5m01s] <------- line it stopped at.

Hours later it still reads this. So I am forced to manually cancel the process.

The output to the command line that was given from the start of the process to aborting the process is given below:

       [mert3419@pplxint9 ttbar]$ ./bin/generate_events
       launch in debug mode
       ************************************************************
       * *
       * W E L C O M E to *
       * M A D G R A P H 5 _ a M C @ N L O *
       * M A D E V E N T *
       * *
       * * * *
       * * * * * *
       * * * * * 5 * * * * *
       * * * * * *
       * * * *
       * *
       * VERSION 2.5.5 20xx-xx-xx *
       * *
       * The MadGraph5_aMC@NLO Development Team - Find us at *
       * https://server06.fynu.ucl.ac.be/projects/madgraph *
       * *
       * Type 'help' for in-line help. *
       * *
       ************************************************************
       INFO: load configuration from /data/atlas/atlasdata/mert3419/software/madgraph5/MG5_aMC_v2_5_5/ttbar/Cards/me5_configuration.txt
       INFO: load configuration from /data/atlas/atlasdata/mert3419/software/madgraph5/MG5_aMC_v2_5_5/input/mg5_configuration.txt
       INFO: load configuration from /data/atlas/atlasdata/mert3419/software/madgraph5/MG5_aMC_v2_5_5/ttbar/Cards/me5_configuration.txt
       Using default text editor "vi". Set another one in ./input/mg5_configuration.txt
       Using default eps viewer "evince". Set another one in ./input/mg5_configuration.txt
       Using default web browser "firefox". Set another one in ./input/mg5_configuration.txt
       generate_events
       The following switches determine which programs are run:
       /--------------------------------------------------------------------------------------------------\
       | 1. Choose the shower/hadronization program: shower = PYTHIA8 |
       | 2. Choose the detector simulation program: detector = OFF |
       | 3. Run an analysis package on the events generated: analysis = No analysis tool interfaced to MG5aMC.|
       | 4. Decay particles with the MadSpin module: madspin = OFF |
       | 5. Add weights to events for different model hypothesis: reweight = OFF |
       \--------------------------------------------------------------------------------------------------/
         Either type the switch number (1 to 5) to change its setting,
         Set any switch explicitly (e.g. type 'madspin=ON' at the prompt)
         Type 'help' for the list of all valid option
         Type '0', 'auto', 'done' or just press enter when you are done.
        [0, auto, done, delphes, delphes=ON, delphes=OFF, shower=OFF, shower=PYTHIA8, shower, detector=OFF, ... ][60s to answer]
       >0
       Do you want to edit a card (press enter to bypass editing)?
       /------------------------------------------------------------\
       | 1. param : param_card.dat |
       | 2. run : run_card.dat |
       | 3. pythia8 : pythia8_card.dat |
       \------------------------------------------------------------/
        you can also
          - enter the path to a valid card or banner.
          - use the 'set' command to modify a parameter directly.
            The set option works only for param_card and run_card.
            Type 'help set' for more information on this command.
          - call an external program (ASperGE/MadWidth/...).
            Type 'help' for the list of available command
        [0, done, 1, param, 2, run, 3, pythia8, enter path][90s to answer]
       >0
       INFO: Update the dependent parameter of the param_card.dat
       Generating 100 events with run name run_20
       survey run_20
       INFO: compile directory
       compile Source Directory
       Using random number seed offset = 201
       INFO: Running Survey
       Creating Jobs
       Working on SubProcesses
       INFO: P1_gg_ttx
       INFO: P1_qq_ttx
       INFO: Idle: 1, Running: 0, Completed: 1 [ current time: 17h54 ]
       INFO: Idle: 0, Running: 1, Completed: 1 [ 0.051s ]
       INFO: Idle: 0, Running: 0, Completed: 2 [ 1.3s ]
       INFO: End survey
       refine 100
       Creating Jobs
       INFO: Refine results to 100
       /data/atlas/atlasdata/mert3419/software/madgraph5/MG5_aMC_v2_5_5/ttbar/bin/internal/gen_ximprove.py:753: DeprecationWarning: object.__new__() takes no parameters
         return super(gen_ximprove, cls).__new__(gen_ximprove_v4, cmd, opt)
/data/atlas/atlasdata/mert3419/software/madgraph5/MG5_aMC_v2_5_5/ttbar/bin/internal/gen_ximprove.py:759: DeprecationWarning: object.__init__() takes no parameters
         super(gen_ximprove, self).__init__(cmd, opt)
       INFO: Generating 100.0 unweigthed events.
       INFO: Effective Luminosity 0.237413146357 pb^-1
       INFO: need to improve 0 channels
       Current estimate of cross-section: 505.448 +- 4.04715406282
           P1_gg_ttx
           P1_qq_ttx
       INFO: Idle: 0, Running: 0, Completed: 0 [ current time: 17h54 ]
       INFO: Combining runs
       INFO: finish refine
       refine 100
       Creating Jobs
       INFO: Refine results to 100
       INFO: Generating 100.0 unweigthed events.
       INFO: Effective Luminosity 0.237413146357 pb^-1
       INFO: need to improve 0 channels
       Current estimate of cross-section: 505.448 +- 4.04715406282
           P1_gg_ttx
           P1_qq_ttx
       INFO: Idle: 0, Running: 0, Completed: 0 [ current time: 17h54 ]
       INFO: Combining runs
       INFO: finish refine
       INFO: Combining Events
         === Results Summary for run: run_20 tag: tag_1 ===

            Cross-section : 505.4 +- 4.047 pb
            Nb of events : 100

       INFO: Running Systematics computation
       INFO: # events generated with PDF: NNPDF23_lo_as_0130_qed (247000)
       INFO: #Will Compute 145 weights per event.
       INFO: # currently at event 0 [elapsed time: 0.033 s]
       INFO: #***************************************************************************
#
# original cross-section: 505.448
# scale variation: +29.9% -21.5%
# central scheme variation: +5.98e-09% -25.9%
# PDF variation: +4.1% -4.1%
#
# dynamical scheme # 1 : 478.134 +29.3% -21.3% # \sum ET
# dynamical scheme # 2 : 396.54 +27.5% -20.4% # \sum\sqrt{m^2+pt^2}
# dynamical scheme # 3 : 505.448 +29.9% -21.5% # 0.5 \sum\sqrt{m^2+pt^2}
# dynamical scheme # 4 : 374.561 +26.9% -20% # \sqrt{\hat s}
#***************************************************************************

INFO: End of systematics computation
store_events
INFO: Storing parton level results
INFO: End Parton
reweight -from_cards
decay_events -from_cards
INFO: Running Pythia8 [arXiv:1410.3012]
No user-defined value for Pythia8 parameter 'JetMatching:nJetMax'. Setting it automatically to 0.
Splitting .lhe event file for PY8 parallelization...
Submitting Pythia8 jobs...
Pythia8 shower jobs: 1 Idle, 0 Running, 0 Done [1 seconds]
Pythia8 shower jobs: 0 Idle, 1 Running, 0 Done [5m01s]
^CTraceback (most recent call last):
  File "./bin/generate_events", line 37, in <module>
rm jobs on queue
    subprocess.call([sys.executable] + ['-O'] + sys.argv)
  File "/usr/lib64/python2.6/subprocess.py", line 481, in call
    return p.wait()
  File "/usr/lib64/python2.6/subprocess.py", line 1307, in wait
    pid, sts = _eintr_retry_call(os.waitpid, self.pid, 0)
  File "/usr/lib64/python2.6/subprocess.py", line 462, in _eintr_retry_call
    return func(*args)
KeyboardInterrupt
[mert3419@pplxint9 ttbar]$ INFO: Stop by the user
stopping all operation
            in order to quit MadGraph5_aMC@NLO please enter exit
INFO: generate_events Stop by the user
quit
INFO: storing files of previous run
gzipping output file: unweighted_events.lhe
INFO: Done
INFO:

INFO:

^C
[mert3419@pplxint9 ttbar]$

text added so you can more easily see where the output to the command line ends
END OF OUTPUT END OF OUTPUT END OF OUTPUT END OF OUTPUT
END OF OUTPUT END OF OUTPUT END OF OUTPUT END OF OUTPUT
END OF OUTPUT END OF OUTPUT END OF OUTPUT END OF OUTPUT
END OF OUTPUT END OF OUTPUT END OF OUTPUT END OF OUTPUT

That was the command line output from running pythia8 taking a unweighted_events.lhe.gz file produced by MadGraph for a pp2ttbar process as input. As I was forced to abort the process I do not have a pythia8 logfile.

The Cards.
The param_card.dat was unaltered from the default.
The run_card.dat had the number of events reduced to 100 and had the ickkw toggled to 1.
The pythia8_card.dat was unaltered from default.
All other cards were also unchanged from default.

The output directory of this run contained the following:
     parton_systematics.log
     run_20_tag_1_banner.txt
     tag_1_pythia8.cmd
     PY8_parallelization
     run_shower.sh
     unweighted_events.lhe.gz

the contents of the run_20_tag_1_banner.txt text file is shown below:

       more text to split up this question more clearly
       BEGGING OF FILE run_20_tag_1_banner.txt text
       BEGGING OF FILE run_20_tag_1_banner.txt text
       BEGGING OF FILE run_20_tag_1_banner.txt text
       BEGGING OF FILE run_20_tag_1_banner.txt text
       BEGGING OF FILE run_20_tag_1_banner.txt text

<LesHouchesEvents version="3.0">
<header>
<!--
#*********************************************************************
# *
# MadGraph5_aMC@NLO *
# *
# Going Beyond *
# *
# http://madgraph.hep.uiuc.edu *
# http://madgraph.phys.ucl.ac.be *
# http://amcatnlo.cern.ch *
# *
# The MadGraph5_aMC@NLO team *
# *
#....................................................................*
# *
# This file contains all the information necessary to reproduce *
# the events generated: *
# *
# 1. software version *
# 2. proc_card : code generation info including model *
# 3. param_card : model primary parameters in the LH format *
# 4. run_card : running parameters (collider and cuts) *
# 5. pythia_card : present only if pythia has been run *
# 6. pgs_card : present only if pgs has been run *
# 7. delphes_cards : present only if delphes has been run *
# *
# *
#*********************************************************************
-->
<MGVersion>
#2.5.5
</MGVersion>
<MG5ProcCard>
#************************************************************
#* MadGraph5_aMC@NLO *
#* *
#* * * *
#* * * * * *
#* * * * * 5 * * * * *
#* * * * * *
#* * * *
#* *
#* *
#* VERSION 2.5.5 2017-05-26 *
#* *
#* The MadGraph5_aMC@NLO Development Team - Find us at *
#* https://server06.fynu.ucl.ac.be/projects/madgraph *
#* *
#************************************************************
#* *
#* Command File for MadGraph5_aMC@NLO *
#* *
#* run as ./bin/mg5_aMC filename *
#* *
#************************************************************
set group_subprocesses Auto
set ignore_six_quark_processes False
set loop_optimized_output True
set loop_color_flows False
set gauge unitary
set complex_mass_scheme False
set max_npoint_for_channel 0
import model sm
define p = g u c d s u~ c~ d~ s~
define j = g u c d s u~ c~ d~ s~
define l+ = e+ mu+
define l- = e- mu-
define vl = ve vm vt
define vl~ = ve~ vm~ vt~
generate p p > t t~
output ttbar
</MG5ProcCard>
<MGProcCard>
#*********************************************************************
# MadGraph/MadEvent *
# http://madgraph.hep.uiuc.edu *
# *
# proc_card.dat *
#*********************************************************************
# *
# This Files is generated by MADGRAPH 5 *
# *
# WARNING: This Files is generated for MADEVENT (compatibility issue)*
# This files is NOT a valid MG4 proc_card.dat *
# Running this in MG4 will NEVER reproduce the result of MG5*
# *
#*********************************************************************
#*********************************************************************
# Process(es) requested : mg2 input *
#*********************************************************************
# Begin PROCESS # This is TAG. Do not modify this line
p p > t t~ #Process
# Be carefull the coupling are here in MG5 convention

end_coup # End the couplings input

done # this tells MG there are no more procs
# End PROCESS # This is TAG. Do not modify this line
#*********************************************************************
# Model information *
#*********************************************************************
# Begin MODEL # This is TAG. Do not modify this line
sm
# End MODEL # This is TAG. Do not modify this line
#*********************************************************************
# Start multiparticle definitions *
#*********************************************************************
# Begin MULTIPARTICLES # This is TAG. Do not modify this line

# End MULTIPARTICLES # This is TAG. Do not modify this line
</MGProcCard>
<MGRunCard>
#*********************************************************************
# MadGraph5_aMC@NLO *
# *
# run_card.dat MadEvent *
# *
# This file is used to set the parameters of the run. *
# *
# Some notation/conventions: *
# *
# Lines starting with a '# ' are info or comments *
# *
# mind the format: value = variable ! comment *
#*********************************************************************
#
#*******************
# Running parameters
#*******************
#
#*********************************************************************
# Tag name for the run (one word) *
#*********************************************************************
  tag_1 = run_tag ! name of the run
#*********************************************************************
# Number of events and rnd seed *
# Warning: Do not generate more than 1M events in a single run *
# If you want to run Pythia, avoid more than 50k events in a run. *
#*********************************************************************
  100 = nevents ! Number of unweighted events requested
 201 = iseed ! rnd seed (0=assigned automatically=default))
#*********************************************************************
# Collider type and energy *
# lpp: 0=No PDF, 1=proton, -1=antiproton, 2=photon from proton, *
# 3=photon from electron *
#*********************************************************************
     1 = lpp1 ! beam 1 type
     1 = lpp2 ! beam 2 type
     6500.0 = ebeam1 ! beam 1 total energy in GeV
     6500.0 = ebeam2 ! beam 2 total energy in GeV
#*********************************************************************
# Beam polarization from -100 (left-handed) to 100 (right-handed) *
#*********************************************************************
     0.0 = polbeam1 ! beam polarization for beam 1
     0.0 = polbeam2 ! beam polarization for beam 2
#*********************************************************************
# PDF CHOICE: this automatically fixes also alpha_s and its evol. *
#*********************************************************************
     nn23lo1 = pdlabel ! PDF set
     230000 = lhaid ! if pdlabel=lhapdf, this is the lhapdf number
#*********************************************************************
# Renormalization and factorization scales *
#*********************************************************************
 False = fixed_ren_scale ! if .true. use fixed ren scale
 False = fixed_fac_scale ! if .true. use fixed fac scale
 91.188 = scale ! fixed ren scale
 91.188 = dsqrt_q2fact1 ! fixed fact scale for pdf1
 91.188 = dsqrt_q2fact2 ! fixed fact scale for pdf2
 -1 = dynamical_scale_choice ! Choose one of the preselected dynamical choices
 1.0 = scalefact ! scale factor for event-by-event scales
#*********************************************************************
# Type and output format
#*********************************************************************
  False = gridpack !True = setting up the grid pack
  -1.0 = time_of_flight ! threshold (in mm) below which the invariant livetime is not written (-1 means not written)
  3.0 = lhe_version ! Change the way clustering information pass to shower.
  True = clusinfo ! include clustering tag in output
  average = event_norm ! average/sum. Normalization of the weight in the LHEF

#*********************************************************************
# Matching parameter (MLM only)
#*********************************************************************
 1 = ickkw ! 0 no matching, 1 MLM
 1.0 = alpsfact ! scale factor for QCD emission vx
 False = chcluster ! cluster only according to channel diag
 4 = asrwgtflavor ! highest quark flavor for a_s reweight
 False = auto_ptj_mjj ! Automatic setting of ptj and mjj if xqcut >0
                                   ! (turn off for VBF and single top processes)
 0.0 = xqcut ! minimum kt jet measure between partons
#*********************************************************************
#
#*********************************************************************
# handling of the helicities:
# 0: sum over all helicities
# 1: importance sampling over helicities
#*********************************************************************
   0 = nhel ! using helicities importance sampling or not.
#*********************************************************************
# Generation bias, check the wiki page below for more information: *
# 'cp3.irmp.ucl.ac.be/projects/madgraph/wiki/LOEventGenerationBias' *
#*********************************************************************
 None = bias_module ! Bias type of bias, [None, ptj_bias, -custom_folder-]
 {} = bias_parameters ! Specifies the parameters of the module.
#
#*******************************
# Parton level cuts definition *
#*******************************
#
#
#*********************************************************************
# BW cutoff (M+/-bwcutoff*Gamma) ! Define on/off-shell for "$" and decay
#*********************************************************************
  15.0 = bwcutoff ! (M+/-bwcutoff*Gamma)
#*********************************************************************
# Apply pt/E/eta/dr/mij/kt_durham cuts on decay products or not
# (note that etmiss/ptll/ptheavy/ht/sorted cuts always apply)
#*********************************************************************
   False = cut_decays ! Cut decay products
#*********************************************************************
# Standard Cuts *
#*********************************************************************
# Minimum and maximum pt's (for max, -1 means no cut) *
#*********************************************************************
 20.0 = ptj ! minimum pt for the jets
 0.0 = ptb ! minimum pt for the b
 10.0 = pta ! minimum pt for the photons
 10.0 = ptl ! minimum pt for the charged leptons
 0.0 = misset ! minimum missing Et (sum of neutrino's momenta)
 0.0 = ptheavy ! minimum pt for one heavy final state
 -1.0 = ptjmax ! maximum pt for the jets
 -1.0 = ptbmax ! maximum pt for the b
 -1.0 = ptamax ! maximum pt for the photons
 -1.0 = ptlmax ! maximum pt for the charged leptons
 -1.0 = missetmax ! maximum missing Et (sum of neutrino's momenta)
#*********************************************************************
# Minimum and maximum E's (in the center of mass frame) *
#*********************************************************************
  0.0 = ej ! minimum E for the jets
  0.0 = eb ! minimum E for the b
  0.0 = ea ! minimum E for the photons
  0.0 = el ! minimum E for the charged leptons
  -1.0 = ejmax ! maximum E for the jets
 -1.0 = ebmax ! maximum E for the b
 -1.0 = eamax ! maximum E for the photons
 -1.0 = elmax ! maximum E for the charged leptons
#*********************************************************************
# Maximum and minimum absolute rapidity (for max, -1 means no cut) *
#*********************************************************************
  5.0 = etaj ! max rap for the jets
  -1.0 = etab ! max rap for the b
 2.5 = etaa ! max rap for the photons
 2.5 = etal ! max rap for the charged leptons
 0.0 = etajmin ! min rap for the jets
 0.0 = etabmin ! min rap for the b
 0.0 = etaamin ! min rap for the photons
 0.0 = etalmin ! main rap for the charged leptons
#*********************************************************************
# Minimum and maximum DeltaR distance *
#*********************************************************************
 0.4 = drjj ! min distance between jets
 0.0 = drbb ! min distance between b's
 0.4 = drll ! min distance between leptons
 0.4 = draa ! min distance between gammas
 0.0 = drbj ! min distance between b and jet
 0.4 = draj ! min distance between gamma and jet
 0.4 = drjl ! min distance between jet and lepton
 0.0 = drab ! min distance between gamma and b
 0.0 = drbl ! min distance between b and lepton
 0.4 = dral ! min distance between gamma and lepton
 -1.0 = drjjmax ! max distance between jets
 -1.0 = drbbmax ! max distance between b's
 -1.0 = drllmax ! max distance between leptons
 -1.0 = draamax ! max distance between gammas
 -1.0 = drbjmax ! max distance between b and jet
 -1.0 = drajmax ! max distance between gamma and jet
 -1.0 = drjlmax ! max distance between jet and lepton
 -1.0 = drabmax ! max distance between gamma and b
 -1.0 = drblmax ! max distance between b and lepton
 -1.0 = dralmax ! maxdistance between gamma and lepton
#*********************************************************************
# Minimum and maximum invariant mass for pairs *
# WARNING: for four lepton final state mmll cut require to have *
# different lepton masses for each flavor! *
#*********************************************************************
 0.0 = mmjj ! min invariant mass of a jet pair
 0.0 = mmbb ! min invariant mass of a b pair
 0.0 = mmaa ! min invariant mass of gamma gamma pair
 0.0 = mmll ! min invariant mass of l+l- (same flavour) lepton pair
 -1.0 = mmjjmax ! max invariant mass of a jet pair
 -1.0 = mmbbmax ! max invariant mass of a b pair
 -1.0 = mmaamax ! max invariant mass of gamma gamma pair
 -1.0 = mmllmax ! max invariant mass of l+l- (same flavour) lepton pair
#*********************************************************************
# Minimum and maximum invariant mass for all letpons *
#*********************************************************************
 0.0 = mmnl ! min invariant mass for all letpons (l+- and vl)
 -1.0 = mmnlmax ! max invariant mass for all letpons (l+- and vl)
#*********************************************************************
# Minimum and maximum pt for 4-momenta sum of leptons *
#*********************************************************************
 0.0 = ptllmin ! Minimum pt for 4-momenta sum of leptons(l and vl)
 -1.0 = ptllmax ! Maximum pt for 4-momenta sum of leptons(l and vl)
#*********************************************************************
# Inclusive cuts *
#*********************************************************************
 0.0 = xptj ! minimum pt for at least one jet
 0.0 = xptb ! minimum pt for at least one b
 0.0 = xpta ! minimum pt for at least one photon
 0.0 = xptl ! minimum pt for at least one charged lepton
#*********************************************************************
# Control the pt's of the jets sorted by pt *
#*********************************************************************
 0.0 = ptj1min ! minimum pt for the leading jet in pt
 0.0 = ptj2min ! minimum pt for the second jet in pt
 0.0 = ptj3min ! minimum pt for the third jet in pt
 0.0 = ptj4min ! minimum pt for the fourth jet in pt
 -1.0 = ptj1max ! maximum pt for the leading jet in pt
 -1.0 = ptj2max ! maximum pt for the second jet in pt
 -1.0 = ptj3max ! maximum pt for the third jet in pt
 -1.0 = ptj4max ! maximum pt for the fourth jet in pt
 0 = cutuse ! reject event if fails any (0) / all (1) jet pt cuts
#*********************************************************************
# Control the pt's of leptons sorted by pt *
#*********************************************************************
 0.0 = ptl1min ! minimum pt for the leading lepton in pt
 0.0 = ptl2min ! minimum pt for the second lepton in pt
 0.0 = ptl3min ! minimum pt for the third lepton in pt
 0.0 = ptl4min ! minimum pt for the fourth lepton in pt
 -1.0 = ptl1max ! maximum pt for the leading lepton in pt
 -1.0 = ptl2max ! maximum pt for the second lepton in pt
 -1.0 = ptl3max ! maximum pt for the third lepton in pt
 -1.0 = ptl4max ! maximum pt for the fourth lepton in pt
#*********************************************************************
# Control the Ht(k)=Sum of k leading jets *
#*********************************************************************
 0.0 = htjmin ! minimum jet HT=Sum(jet pt)
 -1.0 = htjmax ! maximum jet HT=Sum(jet pt)
 0.0 = ihtmin !inclusive Ht for all partons (including b)
 -1.0 = ihtmax !inclusive Ht for all partons (including b)
 0.0 = ht2min ! minimum Ht for the two leading jets
 0.0 = ht3min ! minimum Ht for the three leading jets
 0.0 = ht4min ! minimum Ht for the four leading jets
 -1.0 = ht2max ! maximum Ht for the two leading jets
 -1.0 = ht3max ! maximum Ht for the three leading jets
 -1.0 = ht4max ! maximum Ht for the four leading jets
#***********************************************************************
# Photon-isolation cuts, according to hep-ph/9801442 *
# When ptgmin=0, all the other parameters are ignored *
# When ptgmin>0, pta and draj are not going to be used *
#***********************************************************************
 0.0 = ptgmin ! Min photon transverse momentum
 0.4 = R0gamma ! Radius of isolation code
 1.0 = xn ! n parameter of eq.(3.4) in hep-ph/9801442
 1.0 = epsgamma ! epsilon_gamma parameter of eq.(3.4) in hep-ph/9801442
 True = isoEM ! isolate photons from EM energy (photons and leptons)
#*********************************************************************
# WBF cuts *
#*********************************************************************
 0.0 = xetamin ! minimum rapidity for two jets in the WBF case
 0.0 = deltaeta ! minimum rapidity for two jets in the WBF case
#***********************************************************************
# Turn on either the ktdurham or ptlund cut to activate *
# CKKW(L) merging with Pythia8 [arXiv:1410.3012, arXiv:1109.4829] *
#***********************************************************************
 -1.0 = ktdurham
 0.4 = dparameter
 -1.0 = ptlund
 1, 2, 3, 4, 5, 6, 21 = pdgs_for_merging_cut ! PDGs for two cuts above
#*********************************************************************
# maximal pdg code for quark to be considered as a light jet *
# (otherwise b cuts are applied) *
#*********************************************************************
 4 = maxjetflavor ! Maximum jet pdg code
#*********************************************************************
#
#*********************************************************************
# Store info for systematics studies *
# WARNING: Do not use for interference type of computation *
#*********************************************************************
   True = use_syst ! Enable systematics studies
#
#**************************************
# Parameter of the systematics study
# will be used by SysCalc (if installed)
#**************************************
#
0.5 1 2 = sys_scalefact # factorization/renormalization scale factor
None = sys_alpsfact # \alpha_s emission scale factors
auto = sys_matchscale # variation of merging scale
# PDF sets and number of members (0 or none for all members).
NNPDF23_lo_as_0130_qed = sys_pdf # list of pdf sets
# MSTW2008nlo68cl.LHgrid 1 = sys_pdf
#
</MGRunCard>
<slha>
######################################################################
## PARAM_CARD AUTOMATICALY GENERATED BY MG5 FOLLOWING UFO MODEL ####
######################################################################
## ##
## Width set on Auto will be computed following the information ##
## present in the decay.py files of the model. ##
## See arXiv:1402.1178 for more details. ##
## ##
######################################################################

###################################
## INFORMATION FOR MASS
###################################
Block mass
    5 4.700000e+00 # MB
    6 1.730000e+02 # MT
   15 1.777000e+00 # MTA
   23 9.118800e+01 # MZ
   25 1.250000e+02 # MH
## Dependent parameters, given by model restrictions.
## Those values should be edited following the
## analytical expression. MG5 ignores those values
## but they are important for interfacing the output of MG5
## to external program such as Pythia.
  1 0.000000 # d : 0.0
  2 0.000000 # u : 0.0
  3 0.000000 # s : 0.0
  4 0.000000 # c : 0.0
  11 0.000000 # e- : 0.0
  12 0.000000 # ve : 0.0
  13 0.000000 # mu- : 0.0
  14 0.000000 # vm : 0.0
  16 0.000000 # vt : 0.0
  21 0.000000 # g : 0.0
  22 0.000000 # a : 0.0
  24 80.419002 # w+ : cmath.sqrt(MZ__exp__2/2. + cmath.sqrt(MZ__exp__4/4. - (aEW*cmath.pi*MZ__exp__2)/(Gf*sqrt__2)))

###################################
## INFORMATION FOR SMINPUTS
###################################
Block sminputs
    1 1.325070e+02 # aEWM1
    2 1.166390e-05 # Gf
    3 1.180000e-01 # aS

###################################
## INFORMATION FOR YUKAWA
###################################
Block yukawa
    5 4.700000e+00 # ymb
    6 1.730000e+02 # ymt
   15 1.777000e+00 # ymtau

###################################
## INFORMATION FOR DECAY
###################################
DECAY 6 1.491500e+00 # WT
DECAY 23 2.441404e+00 # WZ
DECAY 24 2.047600e+00 # WW
DECAY 25 6.382339e-03 # WH
## Dependent parameters, given by model restrictions.
## Those values should be edited following the
## analytical expression. MG5 ignores those values
## but they are important for interfacing the output of MG5
## to external program such as Pythia.
DECAY 1 0.000000 # d : 0.0
DECAY 2 0.000000 # u : 0.0
DECAY 3 0.000000 # s : 0.0
DECAY 4 0.000000 # c : 0.0
DECAY 5 0.000000 # b : 0.0
DECAY 11 0.000000 # e- : 0.0
DECAY 12 0.000000 # ve : 0.0
DECAY 13 0.000000 # mu- : 0.0
DECAY 14 0.000000 # vm : 0.0
DECAY 15 0.000000 # ta- : 0.0
DECAY 16 0.000000 # vt : 0.0
DECAY 21 0.000000 # g : 0.0
DECAY 22 0.000000 # a : 0.0
</slha>
<MGGenerationInfo>
# Number of Events : 100
# Integrated weight (pb) : 505.448
</MGGenerationInfo>
</header>
</LesHouchesEvents>

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Do you have any insights into why pythia8 is stalling? I am new so my cards could be wrong but I have my suspicions that I have installed incorrectly.

without ickkw toggled to 1 on the run_card the process completes and pythia outputs an empty hepmc.gz file.

I am using MG5_aMC/v5-2-5 and pythia8.2.

Thank you for taking the time to read all of that.

Best,
Ewan