Summary

Dear whomever this may concern.

We are currently experiencing this error, which when we use ‘start segment’ function, it vanishes the segment as the attached video shows.

It is hard for us to find out the reason why.

All of our 6.x version shows the same error.

Also, 4.x version(which is not attatched) vanishes our entire work.
It messes up the lay, and even when we bake the hair in spline, it vanishes as well.