I think that purplish color is the default for a "retained" section line; meaning that it lost its associativity and is hanging out in space in its last known location. If you fix the associativity, it should return to normal.
It seems that you are right...perhaps this is just one simple view.. just a few dimensions and it is easy to start again.. but for further situations like this one..
is there any way to visualize this sort of links/associations?
How do i recognize which view is ok and which view have issues?
apparently everything up to date.. just green check marks.. what if i change the direction of the hinge line and the view changes?? is this means the view has not lost its association, right?
thanks in advance !
No need to start over. You were so close in the video; you need to use "move segment", not "redefine hinge line". Edit the line, choose move segment (the default), pick the retained line segment, then pick a point to associate the section line (probably the center point of one of the circular edges?). That should fix it.