IndexError: list index out of range while running update-attack.py

While using workbench to integrate with attack website as per the guide, the following occurs while running update-attack.py

clean : ---------------------------------------- 0.00s
matrices : ---------------------------------------- 7.74s
tactics : ---------------------------------------- 0.13s
techniques : ---------------------------------------- Running...Traceback (most recent call last):
File "update-attack.py", line 154, in
ptr'run_module'
File "/home/yash/Downloads/attack-website-master/modules/techniques/init.py", line 37, in run_module
return (techniques.generate_techniques(), techniques_config.module_name)
File "/home/yash/Downloads/attack-website-master/modules/techniques/techniques.py", line 53, in generate_techniques
check_if_generated = generate_domain_markdown(domain['name'], techniques_no_sub, tactics, side_nav_data, notes, deprecated)
File "/home/yash/Downloads/attack-website-master/modules/techniques/techniques.py", line 95, in generate_domain_markdown
generate_technique_md(technique, domain, side_nav_data, tactics[domain], notes)
File "/home/yash/Downloads/attack-website-master/modules/techniques/techniques.py", line 123, in generate_technique_md
technique_dict = generate_data_for_md(technique_dict, technique, tactic_list)
File "/home/yash/Downloads/attack-website-master/modules/techniques/techniques.py", line 239, in generate_data_for_md
tactic = [x for x in tactic_list if x['x_mitre_shortname'] == elem['phase_name']][0]
IndexError: list index out of range