SSE Error navmesh - Recast failed to create contours.

[DaedricGems]

When I press "SELECT TRIANGLES BY INDEX" and then CHECK NAVMESH -> no warnings found.

 

 

When I press TEST NAVMESH ( icon left to big "B" button) and then any npc

and then I press display overlay: it gives this error -> Recast failed to create contours.

http://imgur.com/a/izQkB

 

Any help?