Just ran into this issue in 4.16.1 workaround from Alex3d worked but i just went to File → export selected, closed window and then import button and closed that window again. then i could see my surface types.
Just ran into this issue in 4.16.1 workaround from Alex3d worked but i just went to File → export selected, closed window and then import button and closed that window again. then i could see my surface types.