Adding then deleting a line from a fully constrained sketch makes it unconstrained.

[schmidt.aaronjoseph]

Hey!

I've had this problem with a number of sketches: 

• The sketch has a number of offset curves.
• The sketch is fully constrained.
• If I then draw a line between 2 of the offset curves, and delete the line again, all the offset curve become unconstrained.
• This only seems to happen to sketches that reach a certain level of complexity. It doesn't happen if I make a new sketch, create a couple offset curves and try and re-create the problem. 
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I've attached 3 files. 

1. State 1. Fully constrained.
2. State 2. Added line between 2 offset curves.
3. State 3. Deleted the line. Sketch now unconstrained. 

Note of offset curves:

• I originally was using the Offset Curve feature, and had this problem.
• This time, I just manually re-drew the curves, made the corner radii concentric, and offset the curves manually. Same problem. 

Any ideas? It makes it tough that I can't backtrack into a sketch a delete lines I no longer need.