MadSpin crashed in SUSY decay

Dear MadGraph experts,

I am studying a simple SUSY model and want to decay
gluino > stop t~, stop > t neutralino
with MadSpin, but MadSpin crashed. I'm pasting the debug file and the MadSpin card below.
I'm using MG5 version 3.1.0 but have checked that the same error occurs in version 2.9.2.

I'd be thankful for any tips
Manuel

Notation: q80m = gluino, s323 = stop, q10m = neutralino

Debug file:
#************************************************************
#* MadGraph5_aMC@NLO/MadEvent *
#* *
#* * * *
#* * * * * *
#* * * * * 5 * * * * *
#* * * * * *
#* * * *
#* *
#* *
#* VERSION 3.1.0 2021-03-30 *
#* *
#* The MadGraph5_aMC@NLO Development Team - Find us at *
#* https://server06.fynu.ucl.ac.be/projects/madgraph *
#* *
#************************************************************
#* *
#* Command File for MadEvent *
#* *
#* run as ./bin/madevent.py filename *
#* *
#************************************************************
generate_events run_01
Traceback (most recent call last):
  File "/scratch/programs/mg5/MG5_aMC_v3_1_0/madgraph/interface/extended_cmd.py", line 1544, in onecmd
    return self.onecmd_orig(line, **opt)
  File "/scratch/programs/mg5/MG5_aMC_v3_1_0/madgraph/interface/extended_cmd.py", line 1493, in onecmd_orig
    return func(arg, **opt)
  File "/scratch/programs/mg5/MG5_aMC_v3_1_0/madgraph/interface/madevent_interface.py", line 2474, in do_generate_events
    self.run_generate_events(switch_mode, args)
  File "/scratch/programs/mg5/MG5_aMC_v3_1_0/madgraph/interface/common_run_interface.py", line 7114, in new_fct
    original_fct(obj, *args, **opts)
  File "/scratch/programs/mg5/MG5_aMC_v3_1_0/madgraph/interface/madevent_interface.py", line 2573, in run_generate_events
    self.exec_cmd('decay_events -from_cards', postcmd=False)
  File "/scratch/programs/mg5/MG5_aMC_v3_1_0/madgraph/interface/extended_cmd.py", line 1573, in exec_cmd
    stop = Cmd.onecmd_orig(current_interface, line, **opt)
  File "/scratch/programs/mg5/MG5_aMC_v3_1_0/madgraph/interface/extended_cmd.py", line 1493, in onecmd_orig
    return func(arg, **opt)
  File "/scratch/programs/mg5/MG5_aMC_v3_1_0/madgraph/interface/common_run_interface.py", line 3761, in do_decay_events
    madspin_cmd.import_command_file(path)
  File "/scratch/programs/mg5/MG5_aMC_v3_1_0/madgraph/interface/extended_cmd.py", line 1692, in import_command_file
    self.exec_cmd(line, precmd=True)
  File "/scratch/programs/mg5/MG5_aMC_v3_1_0/madgraph/interface/extended_cmd.py", line 1573, in exec_cmd
    stop = Cmd.onecmd_orig(current_interface, line, **opt)
  File "/scratch/programs/mg5/MG5_aMC_v3_1_0/madgraph/interface/extended_cmd.py", line 1493, in onecmd_orig
    return func(arg, **opt)
  File "/scratch/programs/mg5/MG5_aMC_v3_1_0/madgraph/various/misc.py", line 109, in f_with_no_logger
    out = f(self, *args, **opt)
  File "/scratch/programs/mg5/MG5_aMC_v3_1_0/MadSpin/interface_madspin.py", line 651, in do_launch
    self.options)
  File "/scratch/programs/mg5/MG5_aMC_v3_1_0/MadSpin/decay.py", line 2049, in __init__
    self.generate_all_matrix_element()
  File "/scratch/programs/mg5/MG5_aMC_v3_1_0/madgraph/various/misc.py", line 109, in f_with_no_logger
    out = f(self, *args, **opt)
  File "/scratch/programs/mg5/MG5_aMC_v3_1_0/madgraph/various/misc.py", line 2007, in deco_f_set
    out = f(*args, **opt)
  File "/scratch/programs/mg5/MG5_aMC_v3_1_0/MadSpin/decay.py", line 2705, in generate_all_matrix_element
    mgcmd.exec_cmd(commandline, precmd=True)
  File "/scratch/programs/mg5/MG5_aMC_v3_1_0/madgraph/interface/extended_cmd.py", line 1573, in exec_cmd
    stop = Cmd.onecmd_orig(current_interface, line, **opt)
  File "/scratch/programs/mg5/MG5_aMC_v3_1_0/madgraph/interface/extended_cmd.py", line 1493, in onecmd_orig
    return func(arg, **opt)
  File "/scratch/programs/mg5/MG5_aMC_v3_1_0/madgraph/interface/master_interface.py", line 299, in do_output
    self.cmd.do_output(self, line, *args, **opts)
  File "/scratch/programs/mg5/MG5_aMC_v3_1_0/madgraph/interface/madgraph_interface.py", line 8138, in do_output
    self.finalize(nojpeg, flaglist=flaglist)
  File "/scratch/programs/mg5/MG5_aMC_v3_1_0/madgraph/interface/madgraph_interface.py", line 8438, in finalize
    wanted_couplings)
  File "/scratch/programs/mg5/MG5_aMC_v3_1_0/madgraph/iolibs/export_v4.py", line 895, in convert_model
    model_builder.build(wanted_couplings)
  File "/scratch/programs/mg5/MG5_aMC_v3_1_0/madgraph/iolibs/export_v4.py", line 6323, in build
    self.write_all()
  File "/scratch/programs/mg5/MG5_aMC_v3_1_0/madgraph/iolibs/export_v4.py", line 6353, in write_all
    self.create_param_read()
  File "/scratch/programs/mg5/MG5_aMC_v3_1_0/madgraph/iolibs/export_v4.py", line 8312, in create_param_read
    for param in self.params_ext]
  File "/scratch/programs/mg5/MG5_aMC_v3_1_0/madgraph/iolibs/export_v4.py", line 8312, in <listcomp>
    for param in self.params_ext]
  File "/scratch/programs/mg5/MG5_aMC_v3_1_0/madgraph/iolibs/export_v4.py", line 8297, in format_line
    'value': self.p_to_f.parse(str(parameter.value.real))}
AttributeError: 'str' object has no attribute 'real'
                              Run Options
                              -----------
               stdout_level : 20 (user set)

                         MadEvent Options
                         ----------------
     automatic_html_opening : False (user set)
        notification_center : True
                   run_mode : 2
              cluster_queue : None (user set)
               cluster_time : None (user set)
               cluster_size : 100
             cluster_memory : 100 (user set)
                    nb_core : 8 (user set)
          cluster_temp_path : None

                      Configuration Options
                      ---------------------
               pythia8_path : /scratch/programs/mg5/MG5_aMC_v3_1_0/HEPTools/pythia8 (user set)
                  hwpp_path : None (user set)
                thepeg_path : None (user set)
                 hepmc_path : None (user set)
           madanalysis_path : None (user set)
          madanalysis5_path : None (user set)
            pythia-pgs_path : None (user set)
                    td_path : None (user set)
               delphes_path : None (user set)
        exrootanalysis_path : None (user set)
               syscalc_path : None (user set)
                     lhapdf : /scratch/programs/mg5/MG5_aMC_v3_1_0/HEPTools/lhapdf6_py3/bin/lhapdf-config (user set)
                 lhapdf_py2 : None
                 lhapdf_py3 : /scratch/programs/mg5/MG5_aMC_v3_1_0/HEPTools/lhapdf6_py3/bin/lhapdf-config (user set)
                    timeout : 60
              f2py_compiler : None
          f2py_compiler_py2 : None
          f2py_compiler_py3 : None
                web_browser : None
                 eps_viewer : None
                text_editor : None
           fortran_compiler : None
               cpp_compiler : None
                auto_update : 7 (user set)
               cluster_type : condor
      cluster_status_update : (600, 30)
           cluster_nb_retry : 1
         cluster_local_path : None
         cluster_retry_wait : 300
#************************************************************
#* MadGraph5_aMC@NLO *
#* *
#* * * *
#* * * * * *
#* * * * * 5 * * * * *
#* * * * * *
#* * * *
#* *
#* *
#* VERSION 3.1.0 2021-03-30 *
#* *
#* 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 low_mem_multicore_nlo_generation False
set complex_mass_scheme False
set include_lepton_initiated_processes False
set gauge unitary
set loop_optimized_output True
set loop_color_flows False
set max_npoint_for_channel 0
set default_unset_couplings 99
set max_t_for_channel 99
set zerowidth_tchannel True
set nlo_mixed_expansion True
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~
import model /scratch/runarea/CHM5/test_runs/mymodel
generate p p > q80m q80m
output madspintest
######################################################################
## PARAM_CARD AUTOMATICALY GENERATED BY MG5 ####
######################################################################
###################################
## INFORMATION FOR CQ80MS323T
###################################
BLOCK CQ80MS323T #
      1 1.000000e-01 # cq80ms323t
###################################
## INFORMATION FOR CS323Q10MT
###################################
BLOCK CS323Q10MT #
      1 1.000000e-01 # cs323q10mt
###################################
## INFORMATION FOR MASS
###################################
BLOCK MASS #
      5 4.700000e+00 # mb
      6 1.720000e+02 # mt
      15 1.777000e+00 # mta
      23 9.118760e+01 # mz
      25 1.250000e+02 # mh
      6100300 1.200000e+03 # ms323
      60000101 4.000000e+02 # mq10m
      60000801 2.000000e+03 # mq80m
      1 0.000000e+00 # d : 0.0
      2 0.000000e+00 # u : 0.0
      3 0.000000e+00 # s : 0.0
      4 0.000000e+00 # c : 0.0
      11 0.000000e+00 # e- : 0.0
      12 0.000000e+00 # ve : 0.0
      13 0.000000e+00 # mu- : 0.0
      14 0.000000e+00 # vm : 0.0
      16 0.000000e+00 # vt : 0.0
      21 0.000000e+00 # g : 0.0
      22 0.000000e+00 # a : 0.0
      24 7.982436e+01 # 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 1.279000e+02 # aewm1
      2 1.166370e-05 # gf
      3 1.184000e-01 # as (note that parameter not used if you use a pdf set)
###################################
## INFORMATION FOR YUKAWA
###################################
BLOCK YUKAWA #
      5 4.700000e+00 # ymb
      6 1.720000e+02 # ymt
      15 1.777000e+00 # ymtau
###################################
## INFORMATION FOR DECAY
###################################
###################################
## INFORMATION FOR QNUMBERS 60000101
###################################
BLOCK QNUMBERS 60000101 # q10m
      1 0 # 3 times electric charge
      2 2 # number of spin states (2s+1)
      3 1 # colour rep (1: singlet, 3: triplet, 8: octet)
      4 0 # particle/antiparticle distinction (0=own anti)
###################################
## INFORMATION FOR QNUMBERS 60000801
###################################
BLOCK QNUMBERS 60000801 # q80m
      1 0 # 3 times electric charge
      2 2 # number of spin states (2s+1)
      3 8 # colour rep (1: singlet, 3: triplet, 8: octet)
      4 0 # particle/antiparticle distinction (0=own anti)
###################################
## INFORMATION FOR QNUMBERS 6100300
###################################
BLOCK QNUMBERS 6100300 # s323
      1 2 # 3 times electric charge
      2 1 # number of spin states (2s+1)
      3 3 # colour rep (1: singlet, 3: triplet, 8: octet)
      4 1 # particle/antiparticle distinction (0=own anti)
#
#*************************
# Decay widths *
#*************************
#
# PDG Width
DECAY 1 0.000000e+00
#
# PDG Width
DECAY 2 0.000000e+00
#
# PDG Width
DECAY 3 0.000000e+00
#
# PDG Width
DECAY 4 0.000000e+00
#
# PDG Width
DECAY 5 0.000000e+00
#
# PDG Width
DECAY 6 1.508336e+00
#
# PDG Width
DECAY 11 0.000000e+00
#
# PDG Width
DECAY 12 0.000000e+00
#
# PDG Width
DECAY 13 0.000000e+00
#
# PDG Width
DECAY 14 0.000000e+00
#
# PDG Width
DECAY 15 0.000000e+00
#
# PDG Width
DECAY 16 0.000000e+00
#
# PDG Width
DECAY 21 0.000000e+00
#
# PDG Width
DECAY 22 0.000000e+00
#
# PDG Width
DECAY 23 2.495200e+00
#
# PDG Width
DECAY 24 2.085000e+00
#
# PDG Width
DECAY 25 4.070000e-03
#
# PDG Width
DECAY 6100300 1.789200e-01
# BR NDA ID1 ID2 ...
   1.000000e+00 2 6 60000101 # 0.17892
#
# PDG Width
DECAY 60000101 1.000000e+00
#
# PDG Width
DECAY 60000801 8.038400e-02
# BR NDA ID1 ID2 ...
   5.000000e-01 2 -6 6100300 # 0.040192
   5.000000e-01 2 -6100300 6 # 0.040192

#*********************************************************************
# 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 *
# *
# To display more options, you can type the command: *
# update full_run_card *
#*********************************************************************
#
#*********************************************************************
# 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 *
#*********************************************************************
  10000 = nevents ! Number of unweighted events requested
  0 = 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, 4=photon from muon *
#*********************************************************************
     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
# To see polarised beam options: type "update beam_pol"

#*********************************************************************
# 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
# To see heavy ion options: type "update ion_pdf"
#*********************************************************************
# 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)
  average = event_norm ! average/sum. Normalization of the weight in the LHEF
# To see MLM/CKKW merging options: type "update MLM" or "update CKKW"

#*********************************************************************
#
#*********************************************************************
# Phase-Space Optimization strategy (basic options)
#*********************************************************************
   0 = nhel ! using helicities importance sampling or not.
                             ! 0: sum over helicity, 1: importance sampling
   2 = sde_strategy ! default integration strategy (hep-ph/2021.xxxxx)
                             ! 1 is old strategy (using amp square)
        ! 2 is new strategy (using only the denominator)
# To see advanced option for Phase-Space optimization: type "update psoptim"
#*********************************************************************
# 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)
#*********************************************************************
# Standard Cuts *
#*********************************************************************
# Minimum and maximum pt's (for max, -1 means no cut) *
#*********************************************************************
 {} = pt_min_pdg ! pt cut for other particles (use pdg code). Applied on particle and anti-particle
 {} = pt_max_pdg ! pt cut for other particles (syntax e.g. {6: 100, 25: 50})
#
# For display option for energy cut in the partonic center of mass frame type 'update ecut'
#
#*********************************************************************
# Maximum and minimum absolute rapidity (for max, -1 means no cut) *
#*********************************************************************
 {} = eta_min_pdg ! rap cut for other particles (use pdg code). Applied on particle and anti-particle
 {} = eta_max_pdg ! rap cut for other particles (syntax e.g. {6: 2.5, 23: 5})
#*********************************************************************
# Minimum and maximum DeltaR distance *
#*********************************************************************
#*********************************************************************
# Minimum and maximum invariant mass for pairs *
#*********************************************************************
 {} = mxx_min_pdg ! min invariant mass of a pair of particles X/X~ (e.g. {6:250})
 {'default': False} = mxx_only_part_antipart ! if True the invariant mass is applied only
                       ! to pairs of particle/antiparticle and not to pairs of the same pdg codes.
#*********************************************************************
# Inclusive cuts *
#*********************************************************************
 0.0 = ptheavy ! minimum pt for at least one heavy final state
#*********************************************************************
# 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
#
systematics = systematics_program ! none, systematics [python], SysCalc [depreceted, C++]
['--mur=0.5,1,2', '--muf=0.5,1,2', '--pdf=errorset'] = systematics_arguments ! see: https://cp3.irmp.ucl.ac.be/projects/madgraph/wiki/Systematics#Systematicspythonmodule
# Syscalc is deprecated but to see the associate options type'update syscalc'

MadSpin card:

set max_weight_ps_point 400
decay q80m > t~ s323
decay q80m > t s323~
decay s323 > t q10m
decay s323~ > t~ q10m
decay t > w+ b, w+ > all all
decay t~ > w- b~, w- > all all
decay w+ > all all
decay w- > all all
decay z > all all
# running the actual code
launch