Working on Unit-2, lesson-1. "Out of the gate," I see a chart with a curve the first time I ran the code. When I run it subsequently, I see an empty window like that described in the lesson. Additionally, at least running in Rider, I did not see any exception when running in the debugger. Not a big deal, but it made me wonder if I had screwed something up. Ignored these issues and everything else seemed to work as advertised.