BrokenPipeError when decaying events

Hi,

I was wondering if I could get some help here regarding a problem with a MadGraph process, please. I am working with a 2HDM and find myself currently studying a process that I generate as

generate p p > h2 j j $$ z w+ w- QCD=99 QED=99 (136 processes with 3192 diagrams)

(see, for reference, https://answers.launchpad.net/mg5amcnlo/+question/710124) and the chain of kinematically allowed decays

h2 > h1 z, h1 > b b~, z > l+ l-

as introduced in the MadSpin card.

Now, there seems to be no error in generating the primary process of p p > h2 j j with the parameter settings I choose; i.e. I seem to get a value for the production cross-section. However, when I try to decay the generated h2 via MadSpin into the states pointed out above, I get a BrokenPipeError error:

INFO: generating the production square matrix element
INFO: generate p p > h2 j j $$ z w+ w- QCD=99 QED=99;
INFO: Done 27.14
INFO: generating the full matrix element squared (with decay)
INFO: generate p p > h2 j j $$ z w+ w- QCD=99 QED=99, (h2 > z h1 , h1 > b b~ , z > l+ l- QCD=99) --no_warning=duplicate;
INFO: Done 42.78
INFO: generate matrix element for decay only (1 - > N).
INFO: output standalone_msF /home/ali/MG5_aMC_v3_5_3/PROC_C2HDM_type1_UFO_29/decay_me
INFO: Done 1.193
INFO: Compiling code
INFO: detect independant decays
INFO: Done in 0.0007879734039306641s
INFO:
INFO: Estimating the maximum weight
INFO: *****************************
INFO: Probing the first 75 events
INFO: with 400 phase space points
INFO:
INFO: Event 1/75 : 0.046s
INFO: Event 6/75 : 0.2s
INFO: Event 11/75 : 0.41s
INFO: Event 16/75 : 0.63s
INFO: Event 21/75 : 0.88s
INFO: Event 26/75 : 1.1s
INFO: Event 31/75 : 1.4s
INFO: Event 36/75 : 1.6s
INFO: Event 41/75 : 1.8s
INFO: Event 46/75 : 2s
INFO: Not enough events for at least one production mode.
INFO: This is ok as long as you don't reuse the max weight for other generations.
INFO:
INFO: Decaying the events...
INFO: Total number of events written: 50/50
INFO: Average number of trial points per production event: 0.0
INFO: Branching ratio to allowed decays: 3.70018e-05
INFO: Number of events with weights larger than max_weight: 0
INFO: Number of subprocesses 8
INFO: Number of failures when restoring the Monte Carlo masses: 0
INFO: Number of failures in reshuffling (event skipped): 50
Command "generate_events run_01" interrupted with error:
BrokenPipeError : [Errno 32] Broken pipe
Please report this bug on https://bugs.launchpad.net/mg5amcnlo
More information is found in '/home/ali/MG5_aMC_v3_5_3/PROC_C2HDM_type1_UFO_29/run_01_tag_1_debug.log'.
Please attach this file to your report.
INFO: storing files of previous run
gzipping output file: unweighted_events.lhe
INFO: Done

In the debug.log file, I further find the following:

generate_events run_01
Traceback (most recent call last):
  File "/home/ali/MG5_aMC_v3_5_3/madgraph/interface/extended_cmd.py", line 1546, in onecmd
    return self.onecmd_orig(line, **opt)
  File "/home/ali/MG5_aMC_v3_5_3/madgraph/interface/extended_cmd.py", line 1495, in onecmd_orig
    return func(arg, **opt)
  File "/home/ali/MG5_aMC_v3_5_3/madgraph/interface/madevent_interface.py", line 2403, in do_generate_events
    self.run_generate_events(switch_mode, args)
  File "/home/ali/MG5_aMC_v3_5_3/madgraph/interface/common_run_interface.py", line 7701, in new_fct
    original_fct(obj, *args, **opts)
  File "/home/ali/MG5_aMC_v3_5_3/madgraph/interface/madevent_interface.py", line 2657, in run_generate_events
    self.exec_cmd('decay_events -from_cards', postcmd=False)
  File "/home/ali/MG5_aMC_v3_5_3/madgraph/interface/extended_cmd.py", line 1575, in exec_cmd
    stop = Cmd.onecmd_orig(current_interface, line, **opt)
  File "/home/ali/MG5_aMC_v3_5_3/madgraph/interface/extended_cmd.py", line 1495, in onecmd_orig
    return func(arg, **opt)
  File "/home/ali/MG5_aMC_v3_5_3/madgraph/interface/common_run_interface.py", line 4098, in do_decay_events
    madspin_cmd.import_command_file(path)
  File "/home/ali/MG5_aMC_v3_5_3/madgraph/interface/extended_cmd.py", line 1694, in import_command_file
    self.exec_cmd(line, precmd=True)
  File "/home/ali/MG5_aMC_v3_5_3/madgraph/interface/extended_cmd.py", line 1575, in exec_cmd
    stop = Cmd.onecmd_orig(current_interface, line, **opt)
  File "/home/ali/MG5_aMC_v3_5_3/madgraph/interface/extended_cmd.py", line 1495, in onecmd_orig
    return func(arg, **opt)
  File "/home/ali/MG5_aMC_v3_5_3/madgraph/various/misc.py", line 109, in f_with_no_logger
    out = f(self, *args, **opt)
  File "/home/ali/MG5_aMC_v3_5_3/MadSpin/interface_madspin.py", line 673, in do_launch
    generate_all.run()
  File "/home/ali/MG5_aMC_v3_5_3/MadSpin/decay.py", line 2134, in run
    self.ending_run()
  File "/home/ali/MG5_aMC_v3_5_3/MadSpin/decay.py", line 2158, in ending_run
    self.terminate_fortran_executables()
  File "/home/ali/MG5_aMC_v3_5_3/MadSpin/decay.py", line 4135, in terminate_fortran_executables
    external.stdin.flush()
BrokenPipeError: [Errno 32] Broken pipe
Related File: None

which I honestly do not understand. I should further add that I am running all of this locally (i.e. *not* on a cluster), which seems relevant because any mentions of such errors I find online are usually related to running things remotely. In case it's relevant though I'll add that I have MadGraph installed on an Ubuntu WSL. Would you happen to know what is going on? Thank you very much in advance for any help.

Best regards,
Ali