Error when my events generation gets refined

Dear experts,

I am currently studying Lepton Flavor Violation for the FCC consindering e- e+ --> t t~, where we consider the top quark to decay into a hypothetical W' particle.

When trying to generate events of any type I get the following error:

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* VERSION 2.7.0 2020-01-20 *
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* The MadGraph5_aMC@NLO Development Team - Find us at *
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load MG5 configuration from input/mg5_configuration.txt
Using golem library in /cvmfs/sft.cern.ch/lcg/views/LCG_92/x86_64-slc6-gcc62-dbg/lib
set fastjet to fastjet-config
set lhapdf to lhapdf-config
Using default text editor "vi". Set another one in ./input/mg5_configuration.txt
No valid web browser found. Please set in ./input/mg5_configuration.txt
set automatic_html_opening False --no_save
compute_widths 34 --precision_channel=0.01 --body_decay=4.0025 --path=/storage_mnt/storage/user/odupon/MG5_aMC_v2_7_0/PROC_WEff_UFO_4/Cards/param_card.dat --output=/storage_mnt/storage/user/odupon/MG5_aMC_v2_7_0/PROC_WEff_UFO_4/Cards/param_card.dat
Please note that the automatic computation of the width is
    only valid in narrow-width approximation and at tree-level.
INFO: Get two body decay from FeynRules formula
Results written to /storage_mnt/storage/user/odupon/MG5_aMC_v2_7_0/PROC_WEff_UFO_4/Cards/param_card.dat
INFO: get decay diagram for wp+
Vertexlist of this model has not been searched.Automatically run the model.find_vertexlist()
Found 3 stable particles
No decay is found
No need for N body-decay (N>2). Results are in /storage_mnt/storage/user/odupon/MG5_aMC_v2_7_0/PROC_WEff_UFO_4/Cards/param_card.dat
INFO: Update the dependent parameter of the param_card.dat
WARNING: Failed to update dependent parameter. This might create trouble for external program (like MadSpin/shower/...)
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: P1_emep_bbxepemvlvl
INFO: Idle: 26, Running: 8, Completed: 0 [ current time: 18h51 ]
INFO: Idle: 25, Running: 8, Completed: 1 [ 0.59s ]
INFO: Idle: 21, Running: 8, Completed: 5 [ 4.6s ]
INFO: Idle: 17, Running: 8, Completed: 9 [ 8.5s ]
INFO: Idle: 13, Running: 8, Completed: 13 [ 13s ]
INFO: Idle: 10, Running: 8, Completed: 16 [ 16.2s ]
INFO: Idle: 7, Running: 8, Completed: 19 [ 21.3s ]
INFO: Idle: 5, Running: 8, Completed: 21 [ 29.2s ]
INFO: Idle: 2, Running: 8, Completed: 24 [ 33.9s ]
INFO: Idle: 1, Running: 8, Completed: 25 [ 37.2s ]
INFO: Idle: 0, Running: 6, Completed: 28 [ 41.4s ]
INFO: Idle: 0, Running: 4, Completed: 30 [ 47.1s ]
INFO: Idle: 0, Running: 3, Completed: 31 [ 1m 4s ]
INFO: Idle: 0, Running: 1, Completed: 33 [ 1m 15s ]
INFO: Idle: 0, Running: 0, Completed: 34 [ 1m 24s ]
INFO: Idle: 0, Running: 0, Completed: 34 [ 1m 24s ]
INFO: End survey
refine 10000
Creating Jobs
INFO: Refine results to 10000
INFO: Generating 10000.0 unweighted events.
INFO: Effective Luminosity 2493105.64962 pb^-1
INFO: need to improve 3 channels
- Current estimate of cross-section: 0.00481327375831 +- 6.9755703137e-05
    P1_emep_bbxepemvlvl
INFO: Idle: 6, Running: 8, Completed: 0 [ current time: 18h52 ]
INFO: Idle: 5, Running: 8, Completed: 1 [ 0.88s ]
INFO: Idle: 0, Running: 2, Completed: 12 [ 5.6s ]
INFO: Idle: 0, Running: 0, Completed: 14 [ 22.7s ]
INFO: Idle: 0, Running: 0, Completed: 14 [ 22.8s ]
INFO: Combining runs
INFO: finish refine
Command "generate_events run_01" interrupted with error:
KeyError : 'second_refine_treshold'
Please report this bug on https://bugs.launchpad.net/mg5amcnlo
More information is found in '/storage_mnt/storage/user/odupon/MG5_aMC_v2_7_0/PROC_WEff_UFO_4/run_01_tag_1_debug.log'.
Please attach this file to your report.
INFO:
quit
INFO:
MG5_aMC>

I never got this error before and I haven't touched any of the internal MadGraph files. My MadGraph, however, did just get updated and the error never appeared before the update. Any advice is appreciated.

Kind regards
Olivier Dupon