In the photo, the highlighted line on the right is real, the other one only shows up when I mouse over it. I did not place this line and it is not visible unless I use the "repair sketch" feature and zoom in very close. The real line is not highlighted when I mouse over it, only when I mouse over the phantom line. The point off to the side is supposed to be the endpoint of that line. When I scroll in very close, it jumps around. All of these are manually placed three-point curves.
This and other instances like it are breaking my sketch.
Edit: Attached the actual part file.
EDITED BY MODERATOR: Moved to the Sketching space. Please post to the appropriate space when one exists.