Created attachment 148111 [details] error Lubuntu 20.04 I wanted to repeat the lesson https://www.youtube.com/watch?v=bbc-ZoTBAbc&t=3s This version is installed via Sunaptic. And the other, installed via Snap, has a bug too and does not work. What I wrote about earlier. I can't add an abstraction arrow. Instead, an extra entry appears in the chart.
*** This bug has been marked as a duplicate of bug 420073 ***