Parameters breaks design with certain values

[asiudaisd]

In the attached video.

If I change the parameter to 56 or 57,  it breaks the model in two different ways. 
However, if I change it to 60. It works just fine.
If I change it to 60 and then to 56, it also works just fine.

If I change it to 56 and then 60, it stays broken. 

Why does the model break with certain values and not others?

[jhackney1972 · Accepted solution]

There is no Bug here.  The problem is in your Sketch 31.  The video will explain.  Correct model is attached.

If this answers your question, please select the "Accept Solution" on my post. If you need further help, please ask.

[asiudaisd]

Thanks for pointing out those trouble making tangent and parallel constraints.
I thought I had set it up with a single horizontal constraint, but it must have automatically added those when I did a click and drag when making the line.
I'll keep an eye out for things that don't belong in the sketch next time.