If you see the following error in your terminal it could be related to a previous bug in the Host Minder app.
sudo: unable to resolve host _hostname_: Name or service not known
How to fix:
Disable Host Minder if it is currently enabled.
Be sure your packages are updated by running the following command.
sudo apt update && sudo apt upgrade
Run the following command to ensure that your machine's hostname is listed in the /etc/hosts file.
sed -i "/^127.0.0.1\ localhost$/ s/$/\ $(hostname)/" /etc/hosts
Now you can re-enable Host Minder and choose the preferred Protection Level.