Tesselation error

When I use the displacement, the edge of the body disappears

266209-bandicam-2019-01-22-22-59-00-427.jpg

If I use crack free displacement, it only works in the preview. It"s not work with imported and geometry meshes.

266210-bandicam-2019-01-22-23-00-25-711.jpg

266211-bandicam-2019-01-22-23-14-18-644.jpg

How can I solve this?
Sorry for my bad English.