If you get the above error you can get
and replace the same file (back it up before that) in counterpartyd_build/dist/counterpartyd/lib directory.
Then restart counterpartyd.
Example from Federated Node (Linux):
sudo sv stop counterpartyd
cd ~/counterpartyd_build/dist/counterpartyd/lib/
mv util.py util.py.bkp
sudo sv start counterpartyd
For non-Federated Node setups:
1. On Windows or Linux you would stop counterpartyd with CTRL+C, and start with "counterpartyd server"
2. On Windows or Linux you could download util.py from your browser and “Save As…”