Green line between on curve point and control point?

Curious about what this is?
http://oi42.tinypic.com/ms236b.jpg

Edit: title should be Blue line, my mistake, the screen was on inverse!

That is one of the oldest bugs in Glyphs. But I like it so I didn’t fix it.

This means that the starting point is not set correctly. Reset the starting point or Layer > Correct Path Direction to fix it.

ahh, ok that’s a good one