@awoolwine said: Downloaded LibFredo6 corners yesterday. it was working fine. today it gives me a message "INVALID-no match of edge properties-F+709. ??? This has to do with the setting of the filter of edge properties, which you may need to adjust to select or exclude edges [image: TEzu_FredoCornerFilteredges.png] fredo PS: the F 709 is a trace which I will remove (I use it for debug)