Break apart erases lines

[Indooroopilly24651216r2mo]

Hey guys

As the video shows, break apart for some reason erases about 80% of the lines. its the same lines each time, but I don't know why. I didn't do anything different with those lines, and the rest of the animation has gone by without hitch.

any help is duley appriciated!q

[n. tilcheff]

Try to do it in small sections, i.e. select 1/4 and break apart, then another section and so on.