... from: Paulr1949 Hi Attached is a box file I have been working on for a future club layout together with a screen dump. I was working on the curve from the 7th track from the bottom of the group at top right of the picture and was playing with various transition curve options in order to allow it to meet the second track from the right at the bottom right of the picture. Suddenly this happened- an outline of two railheads running straight between the two. Any ideas on what I've done wrong? Paul 1913_181246_180000000.png Attachment: attach_1245_1691_SJ_2011_11_18_173 6_39_error.box 187 posted: 18 Nov 2011 19:03 from: Paulr1949 After a couple of hit on CTRL-U, I got the original back and it seems to have worked OK since! Paul posted: 18 Nov 2011 20:19 from: Martin Wynne Hi Paul, Thanks for posting the file. It's a long-standing known issue, not related to TDV. Essentially you created a transition curve which was too gentle for the maths processor in your computer. "Too gentle" means the ...