Are you running in production mode?
if so, try doing the following:
FILE="/etc/supervisor/supervisord.conf"
SEARCH_PATTERN="chown=$USER:$USER"
sudo sed -i "5a $SEARCH_PATTERN" "$FILE"
sudo service supervisor restart
yes | sudo bench setup production $USER
bench scheduler enable
bench scheduler resume
bench setup socketio
yes | bench setup supervisor
bench setup redis
sudo supervisorctl reload
This may fix the supervisorctl restart frappe-bench-web error