PISCSI: Error "No Module named bjoern"

If you are using PISCSI on a RPI 3 B+, and no matter what you try the Web interface cannot start...

just have a look at what's happening by typing:

sudo journalctl -f

if you have an error that says something like this:

ModuleNotFoundError: No Module named 'bjoern'

*And then a red line *

piscsi-we-service: Failed with result 'exit-code'

Luckily there's an easy fix. Just run these commands:

sudo systemctl stop piscsi-web
cd ~/piscsi/python/web
sudo rm -rf venv
sudo systemctl start piscsi-web