The import function of Rhino8’s layer state manager does not allow to open layer state (*.lay) files; only *.3dm files.
Rhino8 layer state import window
In Rhino6 this used to work correctly:
The import function of Rhino8’s layer state manager does not allow to open layer state (*.lay) files; only *.3dm files.
Rhino8 layer state import window
In Rhino6 this used to work correctly: